Everest: The Death Zone (1998)

The human body is highly adaptable to change. It adjusts when you vigorously exercise, move in and out of different temperatures, or face stressful situations. But what about when your body is pushed to extremes, like those of climbers attempting to summit Mt. Everest, which rises 8,848 m (29,028 ft) above sea level? In this environment, climbers confront an atmosphere of one-third less oxygen than at sea level and life-threatening, frigid temperatures. This episode of NOVA follows a doctor at Everest's Base Camp who tracks and analyzes the effects of this harsh environment on climbers' bodies and cognitive functions. The data reveal to what extent these climbers' bodies can adapt and survive at high altitudes.

TRANSCRIPT

"Everest: The Death Zone"

PBS Airdate: February 24, 1998
Go to the companion Web site

During the following program, look for NOVA's Web markers which lead you to more information at our Web site.

ANNOUNCER: Tonight on NOVA, Everest. In 1996, eight died in a single day. N...

(read more)

The human body is highly adaptable to change. It adjusts when you vigorously exercise, move in and out of different temperatures, or face stressful situations. But what about when your body is pushed to extremes, like those of climbers attempting to summit Mt. Everest, which rises 8,848 m (29,028 ft) above sea level? In this environment, climbers confront an atmosphere of one-third less oxygen than at sea level and life-threatening, frigid temperatures. This episode of NOVA follows a doctor at Everest's Base Camp who tracks and analyzes the effects of this harsh environment on climbers' bodies and cognitive functions. The data reveal to what extent these climbers' bodies can adapt and survive at high altitudes.

TRANSCRIPT

"Everest: The Death Zone"

PBS Airdate: February 24, 1998
Go to the companion Web site

During the following program, look for NOVA's Web markers which lead you to more information at our Web site.

ANNOUNCER: Tonight on NOVA, Everest. In 1996, eight died in a single day. Now, NOVA takes you back to explore the effects of altitude on the body and mind.

DAVID BREASHEARS: —before he had the nerve to walk on Carol's door.

HOWARD DONNER: Excellent, David.

ANNOUNCER: And a new drama unfolds. Will the summit claim a new victory?

HOWARD DONNER: What's going on, Ed?

ED VIESTURS: David's dying.

HOWARD DONNER: Breathing quickly right now won't help you, Carter, and I know this is really scary.

ANNOUNCER: Everest—The Death Zone.

Major funding for NOVA is provided by the Park Foundation. Dedicated to education and quality television.

This program is funded in part by Northwestern Mutual Life, which has been protecting families and businesses for generations. Have you heard from the Quiet Company? Northwestern Mutual Life.

And by the Corporation for Public Broadcasting, and viewers like you.

NARRATOR: Five and a half miles above sea level. The high Himalayas stand fixed against the wind and clouds. The air is so thin it is not life-sustaining. Within hours, the living begin to deteriorate. But humans come here, and struggle for each breath to stand briefly, on the highest point on Earth.

DAVE CARTER: It's a living hell. The only way to describe it is an utter exhaustion. You really don't care if you die or if you just sit down and don't go any further.

NARRATOR: In 1996, eight people died in a single day on Everest. Scientists believe many, if not all, of those deaths could have been due to hypoxia, or lack of oxygen to the brain.

PETER HACKETT: Judgement becomes impaired, a person becomes confused. They don't even know where they are as it gets worse. People hallucinate. So, all sorts of mental changes can take place as the brain starts to become more and more abnormal.

ED VIESTURS: It's a very slow and arduous process. You take a step. You breathe. You take another step. That's all your mind is occupied with is taking each individual step.

NARRATOR: For every six successful summits on Everest, one person will die. With more people climbing into the Death Zone, above 26,000 feet, one critical question is how oxygen deprivation affects the brain. David Breashears, a high altitude climber and filmmaker, has stood on top of Everest three times.

DAVID BREASHEARS: It's just hard work. Everything about being at altitude is hard. We go up with the best technology available to us, the best training. And you can still end up frozen to death at 27,500 feet. That's what makes Everest Everest.

NARRATOR: David was making the IMAX film, Everest, last year when a storm claimed eight climbers' lives. He helped rescue some, but others were beyond help. He is returning to film and will lead an expedition that will explore the effects of altitude on the body and mind.

DAVID BREASHEARS: Everyone thinks that they're thinking very clearly up high, and yet, by virtue of going up into that atmosphere, you greatly increase your likelihood for making an error.

NARRATOR: On the early Everest expeditions, climbers trekked for weeks to get to the base of the mountain. Today, they fly into a Sherpa village at 9,000 feet. It will take 10 days to ascend the 9,000 feet in elevation to Everest Base Camp. Base Camp is a temporary city of tents housing 300 people to support nine expeditions. The accommodations may be crude, but most teams have a satellite link to the outside world.

DAVID BREASHEARS: It looks like there are about 30 people standing there just below the football field there.

DAVE CARTER: Yeah, I see them.

NARRATOR: David Breashears meets up with his team members, and they scope out the route of the mountain.

DAVE CARTER: What do you guys think about the upper part there before Camp I?

NARRATOR: David Carter, from Indiana, is returning to Everest after an unsuccessful attempt in 1991.

ED VIESTURS: We always put ladders there and that's the toughest part of the whole Icefall there.

NARRATOR: Ed Viesturs will be guiding Carter. Considered one of today's premier high altitude mountaineers, Ed has climbed Everest four times—twice without oxygen.

ED VIESTURS: Yeah, it's a big flat area, and it doesn't really collapse. It just sinks. I mean, big sections of it just kind of disappear.

NARRATOR: Jangbu Sherpa climbed Everest for the second time on David's last expedition. He is in charge of the large Sherpa staff that will support the team. These climbers will take part in a battery of scientific tests that will gauge their performances at altitude. Ed Viesturs lives and trains in Seattle. Two weeks before leaving for the mountain, the climbers joined him at the University of Washington for baseline tests. Dr. Brownie Schoene looks for physiological clues that determine who will perform well at altitude. One determinant is lung capacity.

BROWNIE SCHOENE: Is it important to have big lungs? Yes, it is, because in that regard, you can move more air, obtain more oxygen within the lungs, and then, the blood can pick up and deliver it to the muscle tissues.

NARRATOR: When we breathe in, oxygen molecules pass through the lungs into the air sacs. Here, purple oxygen-deficient blood cells become revitalized and red with oxygen, and are pumped by the heart through out the body. Dr. Schoene measures the climbers' heart rates and ability to work. Carter is well above average. At the elite level are Ed Viesturs and David Breashears.

BROWNIE SCHOENE: The elite high altitude climber can trudge through the snow, break trail, climb up a cliff at their maximum capability for hours.

NARRATOR: High on Everest, many climbers approach their maximum heart rate just gasping in the thin air. Some may collapse, unable to go on.

BROWNIE SCHOENE: All right. Good job. Good job.

NARRATOR: The amount of oxygen in Carter's blood is measured by Dr. Howard Donner.

HOWARD DONNER: Carter, this little machine that goes "beep" next to you is an oximeter. The top number here is your saturation, which is a measurement of the amount of oxygen in your blood. A hundred percent means that you're completely saturated, which is what we would expect close to sea level. As you go higher, this number is going to drop. This lower number is your pulse. And you see, you have a nice, slow pulse at 63, which is normal for you resting. And as you go up in altitude, a normal response is to see your pulse rate go up.

NARRATOR: Carter is now given a decreased level of oxygen to simulate going to high altitude. His body strives to get more oxygen. As Carter's blood oxygen saturation falls, his breathing increases and his heart speeds up, trying to pump more blood made red with oxygen to his organs. Over time, more oxygen-carrying blood cells will be produced to carry the oxygen where it is most needed, to the muscles and brain. These physiological changes are called acclimatization, and they enable a person to survive at high altitude.

BROWNIE SCHOENE: OK, you're getting a little bit higher altitude. Are you feeling all right? OK.

NARRATOR: Due to this sudden exposure to high altitude, Carter's oxygen saturation plummets. He will ultimately pass out from the lack of oxygen to his brain.

PETER HACKETT: We've found some abnormalities previously in high altitude climbers.

NARRATOR: Dr. Peter Hackett addresses the climbers on the effects of decreased oxygen to the brain.

PETER HACKETT: One of the more pressing questions in high altitude medicine is, does climbing to extreme altitude cause brain damage? And we're going to be looking at that in a number of ways. One is by MRI scans. Some work indicates that some climbers who go to extreme altitude without oxygen do come back with slightly smaller brains. If cells of the brain actually die, the brain will get smaller. That's what happens with strokes and other things that cause brain cells to die. So, we'll look at the volumes of the brain by these special scans. These are unusual people, and they're going to a very unusual place. So, there are some opportunities here. David and Ed have been to altitude many times, and we might expect them to react a little bit differently than David Carter, who is a relative newcomer at these kind of extreme altitudes.

DAVE CARTER: I've lived by the river for 20 years.

NARRATOR: Psychometric testing will reveal subtle changes in the climbers' abilities to process information as they go higher.

GAIL ROSENBAUM: What we will expect to see is that there is a slowing in speech. There will be a slowing in reaction time. We may see a lot of misspeaks. They won't say things quite the way they would at sea level. There will be slurring and hesitations. (to Dave Carter) This one's a little more difficult. This time, what you're going to do is go down the columns, and you're going to say the color that you see. You have to disregard the word you see. Tell me the color that the word is printed in. OK?

DAVE CARTER: OK.

GAIL ROSENBAUM: Go ahead.

DAVE CARTER: Blue. Red. Green. Blue. Red. Blue. Green. Red. Green. Blue. Green. Blue, blue —

GAIL ROSENBAUM: Stop. (laughter) Isn't that fun?

DAVE CARTER: Whew, that's going to be fun at altitude.

GAIL ROSENBAUM: Isn't that fun? If Charles beats David in a sprint, which man is the faster runner?

ED VIESTURS: Charles.

PETER HACKETT: People like Ed Viesturs and others who make a career out of doing these very high peaks without oxygen may have some long-term brain abnormalities. Some studies indicate that they do have very minor, subtle, cognitive dysfunction, and it can be found only on psychometric testing. There's nothing obvious. And their MRIs show that there can be structural changes. We have yet to have a good correlation between the MRI structural changes and the cognitive changes. That's going to take more time, more studies, more research like we're doing now.

NARRATOR: Dr. Howard Donner treks into Base Camp, where he will be stationed to monitor the health of the climbers.

DAVID BREASHEARS: Howard! You made it! Man, you're moving like an old man.

HOWARD DONNER: I'm not ready to speak in coherent sentences, OK? So, go easy.

DAVID BREASHEARS: Welcome to Base Camp.

HOWARD DONNER: Thanks, man. Good to see you.

DAVID BREASHEARS: This is Jangbu, our Sirdar.

JANGBU SHERPA: Nice to meet you.

HOWARD DONNER: Jangbu. Howard Donner. Good to meet you.

DAVID BREASHEARS: You know, you look blue.

JANGBU SHERPA: Thanks.

DAVID BREASHEARS: Here, give me your hand. I've got a pulse oximeter here.

HOWARD DONNER: I don't trust you with medical devices.

DAVID BREASHEARS: Oh, God, look at you. You're alive.

HOWARD DONNER: OK. Good. That's always good.

DAVID BREASHEARS: You know, your saturation level is 74, and your pulse is about 85.

HOWARD DONNER: All right.

NARRATOR: A blood oxygen level of 74% would be alarming at sea level, but is normal for someone who has just reached 18,000 feet.

DAVID BREASHEARS: Well, would you like some tea?

HOWARD DONNER: Thanks, David.

DAVID BREASHEARS: We'll get you warmed up.

NARRATOR: As Howard acclimatizes over the next few days, the level of oxygen in his blood should increase. If it doesn't, he may become with acute mountain sickness.

PETER HACKETT: The early warning signs of mountain sickness are primarily headache followed by dizziness, trouble sleeping, and lack of appetite. And then, as it progresses, one develops a more severe headache, nausea and vomiting, and trouble with the balance or coordination. And that is the hallmark sign of progression to definite cognitive problems.

TREKKER 1: I've had altitude sickness before, and I know how bad a headache can get.

TREKKER 2: The two things that really affect you are shortage of breath and the lack of sleep.

TREKKER 3: Sometimes you rest, and you feel OK. Then, you start walking and it's not OK. (laughter)

TREKKER 4: After, my head has gone to bigger, like this.

TREKKER 5: And I experienced the most shocking headache I've ever had in my life. And I felt sick.

TREKKER 4: In the nighttime, I took two aspirin. After that, I never suffered myself get headache. Now, I'm fine.

NARRATOR: As symptoms get worse, a portable hyperbaric chamber, known as a Gamow Bag, can help.

HOWARD DONNER: What's your altimeter say before you get in?

DOUG ROVIRA: Let's see. We're about 17,600 feet.

HOWARD DONNER: All right.

NARRATOR: The bag is inflated to increase the pressure inside. This results in a higher density of oxygen molecules.

HOWARD DONNER: Doug, why don't you watch your altimeter and let us know in a moment what it's telling us?

DOUG ROVIRA: Well, we're dropping fast.

NARRATOR: This simulates a descent of several thousand feet, where the ambient air holds more oxygen.

HOWARD DONNER: Doug, what's your altitude?

DOUG ROVIRA: I'm at about 15,300 feet now.

HOWARD DONNER: At this altitude, pumping this bag up to 2 PSI will bring a patient down to an altitude inside the bag of about 8,000 lower than we are here. Doug, what altitude are you at?

DOUG ROVIRA: We're at 10,900 feet.

HOWARD DONNER: Most of the time, putting a patient in for a number of hours, they're going to get some benefit. Let's pretend Doug couldn't walk because of severe forms of mountain sickness. We put him in for four or five hours, and now he's able to walk down the hill under his own power. So, that's a big help. OK, Doug, I'm going to stop pumping and slowly deflate.

NARRATOR: Within seconds, the pressure decreases, and the patient returns to 17,600 feet.

HOWARD DONNER: Are your ears OK, Doug?

DOUG ROVIRA: I'm fine.

HOWARD DONNER: Good. So, he's back to Base Camp. You can tell by the fact that there's no more tension here.

DAVID BREASHEARS: Lakba.

LAKBA: Yes, sir?

DAVID BREASHEARS: Can I have a little tea, please?

LAKBA: Yes.

DAVID BREASHEARS: Thank you very much.

LAKBA: You're welcome, sir.

DAVID BREASHEARS: It's 5:30 in the morning here at Base Camp. We'll be doing a little filming today with Jangbu. That's why I'm here. We've got a harness on, our boots, and our crampons. And those are all our tools for the ice fall. And so, I have to eat and drink and get ready to go.

NARRATOR: The Khumbu Icefall is a steep glacier, riddled with deep crevasses and huge ice blocks. It can only be traversed with the use of ladders and rope fixed and maintained by a team of Sherpas. It is here at the beginning of the climb where the greatest objective dangers on Everest lie. On this section, four ladders are strapped together to help climbers scale a 100-foot wall of ice. Jangbu and David use mechanical ascenders to climb up the fixed ropes. This is called jumaring. The Icefall is a jigsaw puzzle of giant blue ice puzzle pieces the size of houses, weighing some 30 tons each. Without warning, the blocks can shift, and crevasses cave in, taking climbers with them. David jumars up the last pitch of the Icefall to arrive at Camp I.

DAVID BREASHEARS: OK, everybody down there. This is David from Camp I, ready to proceed with the high altitude tests. And I wanted to start out with giving you my current pulse oximeter reading. Do you copy? And how are you down there?

JENNY: Yeah, we copy, and we're ready to record your pulse oximeter readings. Over.

DAVID BREASHEARS: Hi, Jenny. We really miss you up here. I'm going to stick this thing on my finger, so stand by. My heart is racing because I have to take this damn test up here, and I'm nervous as hell. Oops, it just went up. So, Jenny, I have it on my finger. The oximeter reading is 80. A more realistic reading for my pulse was, a few minutes, was 78. But now that I have to take this test and I get all this test anxiety, my pulse is racing at 104.

DAVE CARTER: Green. Red. Blue. Red. Green. Red. Blue. Green. Red.

NARRATOR: Along with Ed Viesturs, David Carter has also reached Camp I.

HOWARD DONNER: Carter, this is true and false. I just want you to read the number of each question and tell me whether it's true or false. You have 60 seconds. Go.

DAVE CARTER: Fifty-one is false, 52 is false, 53 is false, 54 false, 55 false, 56 true, 57 false, 58 false—true. Fifty-eight is true, 59 true.

GUY COTTER: Oh, hi, ED.

ED VIESTURS: Hi...

GUY COTTER: Have a good sleep?

ED VIESTURS: Yeah.

GUY COTTER: Guess where we're going?

ED VIESTURS: (whispers) Base Camp.

GUY COTTER: (whispers back) Base Camp.

ED VIESTURS: Yeah...

GUY COTTER: Yee-haw.

ED VIESTURS: Oxygen. Warmth. Cotton clothing.

GUY COTTER: Wow.

ED VIESTURS: Shower. (laughter)

GUY COTTER: Ooh! It's just down there.

NARRATOR: At the top of the Icefall, there is a bottleneck of climbers. Ed Viesturs puts on his pack at the back of the line.

ED VIESTURS: It's amazing. You know, you're on Mount Everest, and you're waiting in line like this.

NARRATOR: It's only one at a time on the ropes. Ed, David, and Carter all descend back down to Base Camp from Camp I. This will be the first of many trips through the Icefall in their long schedule of acclimatization. It takes time for the body to adapt to higher and higher altitudes. Climbers will typically ascend to Camp I twice from Base Camp. They move up to Camp II and sleep there several nights before moving to Camp III. Before their final push to the summit, climbers descend to Base Camp to rest and gain their strength before trying for the summit. While climbing down through the Icefall, the climbers cross paths with a line of Sherpas bearing loads for the higher camps. Sherpa is the name for the indigenous people who live in the Everest region. Although they adapt well to altitude, they are not immune to its debilitating effects. If they push themselves to go up too quickly, they too can suffer from acute mountain sickness. At Base Camp, the climbers hear the disturbing news of a Sherpa who was found near death, lying in the middle of the trail.

DOUG ROVIRA: When I saw him, his eyes—His pupils were fixed and dilated. He barely had a pulse. And he died several minutes after I got there. I think he had high altitude pulmonary edema.

PETER HACKETT: With pulmonary edema, the blood vessels in the lungs start to leak. They leak this plasma fluid that is tinged with red blood cells, so it's a little pinkish. And the air sacs start to fill up with—in different parts of the lung, usually to the right first, then the left. And eventually, they all fill up with fluid. The person starts coughing this pink, frothy sputum, can't get any air at all. Their blood oxygen level drops, and they go into cardiovascular collapse and die.

DOUG ROVIRA: With each breath, he was blowing bubbles through the fluid in his nostrils and mouth. He was drowning in—He was drowning in his own secretions from high altitude pulmonary edema.

NARRATOR: The treatment is descent. If the patient can't walk, then oxygen or a Gamow bag must be used.

SAYACK KOO: Lakpa, hi. Can I check your saturation again?

LAKPA: Mmm-hmm. Thank you.

NARRATOR: The Malaysian expedition doctor measures a sick Sherpa's blood oxygen saturation.

SAYACK KOO: How are you feeling?

LAKPA: All right. Thank you.

SAYACK KOO: Good. Well, on oxygen, he's now got a saturation of about 91%, which is considerably different than what it was yesterday.

HOWARD DONNER: This morning at breakfast, we noticed a team carrying a sick Sherpa—This is Lakpa—by our camp. And we're now at the helicopter landing zone with Dr. Sayack Koo. Sayack, what went on with Lakpa?

SAYACK KOO: Well, he was very ill indeed when we came across him. He was a bit confused. He was quite ashen gray. He was quite breathless as well. And we checked his saturations, and to my alarm, it was 20%. We slapped some oxygen on him and it came up to about 70% or 80% with three or four liters a minute. And because he was able to tolerate lying flat, we decided to put him in the Gamow bag, which we did for two hours.

HOWARD DONNER: And how did he respond to the Gamow?

SAYACK KOO: He did very well. He was comfortable in it, but the fact that he had symptoms on both sides of his lungs and the fact that he was so unwell and so desperately short of oxygen, we treated him for pulmonary edema.

NARRATOR: When a helicopter arrives at Base Camp, it means a person is in need of immediate evacuation. And for Lakba, a quick descent to Katmandu will save his life. Pilots don't hesitate long here, and they breathe supplemental oxygen. If suddenly exposed to the altitude of Base Camp, the pilot could become desperately ill from acute mountain sickness. In the early morning freeze, the climbers silently put on their crampons to climb up through the Icefall for the last time. The team has been on Everest for several weeks, acclimatizing at the higher camps. Time is running out for an attempt on the summit. Carter has developed a high altitude cough, which he knows could jeopardize his chances of completing the climb.

DAVE CARTER: It's a real violent cough. It comes from deep within, and you can't control it. My main concern right now is, when I get higher, the cough will get worse. And I'm worried about breaking a rib or vomiting or something.

NARRATOR: A chilling reminder of how dangerous Everest can be, human remains resurface from the depths of the moving Icefall.

HOWARD DONNER: I came upon this the other day in the glacier. It's the obvious remains of a climber, spread out around this area. This is an inner boot made out of a synthetic material, making it probably 80s vintage. And there are still portions of the bony structure of the foot inside. Right here, maybe the most obviously human portion of this skeleton is the head of the femur. And over here, a tibia and a fibula still intact, still together. And this kind of stuff is spilling out all the time, and a reminder of some of the drama that goes on up in the Icefall.

NARRATOR: The climbers bypass Camp I and enter the Western Cwm on their way to Camp II. This high glacial valley is transected by massive lateral crevasses.

DAVID BREASHEARS: How are you feeling, Ed?

ED VIESTURS: Oh, pretty good. It was a long day. It's about 12:30. I started at 5:00 a.m., so it's been a long day.

DAVID BREASHEARS: Where did you start from?

ED VIESTURS: Base Camp.

DAVID BREASHEARS: Don't you have something really fun to do today?

ED VIESTURS: No. Nothing fun. Just relaxing.

DAVID BREASHEARS: I thought you were going to do some testing up here.

ED VIESTURS: Oh, yeah. We've got to do some testing. That's right.

DAVID BREASHEARS: What kind?

ED VIESTURS: Oh, mental testing. Reading some lists and memorizing and stuff like that.

DAVID BREASHEARS: How do you think you're going to do?

ED VIESTURS: I have no idea. We'll soon find out.

JENNY: OK, Carter. The action of the brave cyclist kept a small boy from being hit by a 10-ton truck.

DAVE CARTER: The action of the brave cyclist kept a small boy from being hit by a 10-ton truck.

LIESL: If Daphne walks twice as fast as Margaret and they are the only two people in a race, who is most likely to finish last?

DAVID BREASHEARS: Margaret.

ED VIESTURS: Ed Viesturs.

JENNY: OK. Now, you know for this test, David, you're going to try and count the low tones, and ignore the high tones.

TONE TEST: (tones can be heard)

DAVID BREASHEARS: Four.

GUY COTTER: Today, I'm suffering badly. We're up at six and a half thousand meters, and often, one feels fairly poorly here anyway. I think I'm suffering from AMS, acute mountain sickness, which with vomiting and diarrhea means that I couldn't drink or eat anything. So, I'm feeling a bit weak. This is the part of high altitude mountaineering that isn't nice—being sick. It's hard enough as it is, but when you're sick as well, all your reserves are gone, and it's very hard to catch up.

NARRATOR: If Guy Cotter's symptoms get worse, he will have to descend. There is a delicate balance between acclimatization and physical decline. Climbers know that they can only stay at altitude for so long.

DAVE CARTER: Yeah, I'm nervous. I don't know how I'm going to perform. I'm also nervous that we're sitting down here and—and my body is slowly deteriorating the longer we stay at this altitude. And I slowly get weaker and weaker.

PETER HACKETT: Humans will start to deteriorate because of the high altitude at around 17,000 feet. Sleeping becomes a problem. Muscle wasting takes place. Weight loss takes place. This process of deterioration takes place much more quickly, the higher altitude that one goes to. So, over at 26,000 feet, it's called the Death Zone because acclimatization is essentially impossible.

DAVE CARTER: We're going to Camp III tomorrow. We're going to get up early around—We're going to get out of here probably about six o'clock. (coughs) I'm on an antibiotic now. I ended up getting a pretty good headcold about three days ago. And yesterday, I was really feeling pretty bad when I came in to Camp II. I was dehydrated and basically just weak from the cold. But the antibiotic's been kicking in, and I'm feeling pretty good today, and looking forward to going tomorrow.

NARRATOR: In the morning, they march to the top of the Western Cwm, where they begin the arduous ascent of the Lhotse Face.

DAVE CARTER: Carter to Base. Do you copy?

HOWARD DONNER: Dave, this is Base. Where are you guys? Over.

DAVE CARTER: Hey, Doc, it's Dave. We're at basically the bottom of the Lhotse Face, where elevation is at 22,300, and it's about 8 o'clock in the morning.

HOWARD DONNER: We got that, dude. How are you feeling overall? Over.

DAVE CARTER: Oh, not too bad. I could be feeling a little bit better right now.

HOWARD DONNER: We're going to need the oximetry data if you have it. Over.

DAVE CARTER: Pulse was around 140 when I rolled in, and blood oxygen saturation was at 60. Over.

NARRATOR: Sixty percent is low, but Howard is hopeful that Carter's saturations will improve over time. David Breashears interviews Carter an hour below Camp III.

DAVID BREASHEARS: How does it feel?

DAVE CARTER: Oh, it's tiring. I feel I've felt better. (coughs) Whew.

DAVID BREASHEARS: What's it like climbing at altitude?

DAVE CARTER: Ah. Yeah, it's just slow. You're winded, dehydrated, losing your voice, coughing. But the views make it worth it.

NARRATOR: Camp III sits halfway up the Lhotse Face, a 45-degree wall of glacial blue ice.

DAVID BREASHEARS: OK, let's huff and puff it up here.

NARRATOR: The pace is slow as Ed and Carter ascend into thin air. The route is fixed with ropes and they fall into the rhythmic movement of kicking steps, pulling, and stepping up.

ED VIESTURS: Finally at Camp III.

DAVE CARTER: Yeah.

ED VIESTURS: Good job.

DAVE CARTER: It's good to be here.

ED VIESTURS: We've got to get some snow and melt some water for those guys coming up.

DAVE CARTER: OK.

ED VIESTURS: Be careful walking around here, though. It's kind of steep, especially without crampons on.

NARRATOR: Many climbers have died here, slipping off the face from one poorly placed step.

DAVID BREASHEARS: Don't you think this is a little absurd? I'm sitting on this little ledge out here in front of my tent at 24,000 feet. I'm ready.

HOWARD DONNER: The video camera captured the bank robbers during daylight robbery of the First Avenue Bank.

DAVE CARTER: The video camera captured the daring bank robbers' robbery of the First National Bank. Oh, oh...

HOWARD DONNER: The action of the brace cyclist kept a small boy from being hit by the 10-ton truck.

DAVID BREASHEARS: The action of the brave cyclist—helped save the boy—Let's see. I know I have to say all I know—prevented the boy being hit by the 10-ton truck. Oh...shit. It's just hard work. Everything about being at altitude is hard. I can't show you that there's no oxygen molecules in the air here. There is only 35% of the oxygen you're breathing down here at sea level available to me right now. We have to finish this expedition. The Icefall is going to close. Our permit's up. We have been here a long time, but we're also extremely cautious, and we're not going to push it one bit. We'll do our research as high as we can, and go home knowing we've done the best we can.

GUY COTTER: Mmmm...

ED VIESTURS: How did you sleep?

GUY COTTER: Good. Yeah. The oxygen really helped. It was great. Oh, yeah. Oh...

HOWARD DONNER: Carter, this is Howard. How do you feel your breathing is going, relative to this upper respiratory infection? Over.

DAVE CARTER: Real good now. A lot better. Howard, it was a lot worse when I was—You know, I'd wake up after two hours, and I felt like I had a lot of shit in my throat, and I'd cough it up. It's kind of a hard chunk, snot-type shit. It was yellow. Over.

HOWARD DONNER: It sounds like maybe you're clearing this stuff out. Over.

DAVE CARTER: Yeah. After a few hot drinks and, like getting off Os and breathing through my nose, I feel a lot better.

HOWARD DONNER: Great, dude. I don't need to tell you this, but just stay hydrated and cough that shit out of there. I'll give you back to Kate.

DAVE CARTER: All righty.

KATE: Carter, where are you now?

DAVE CARTER: I—I don't know. No, I'm kidding. We're at Camp III. We're getting ready to move out.

NARRATOR: Carter is about to go higher than he has ever been before. Looking up the route, some 50 climbers clamor towards the highest camp on the mountain. This makes David Breashears and Ed Viesturs very nervous. They witnessed last year that crowded ropes on Everest can be deadly. This year, it seems nothing has changed. As climbers wait their turn on the ropes, they increase their chances of becoming hypoxic. Tonight, they will all leave camp and climb toward the summit. David and Ed climb into the Death Zone, an altitude where humans are only transient visitors. The tents of Camp IV finally come into view. It has taken nearly two months for the climbers to reach this point. And what will transpire over the next 24 hours will change their lives. Oxygen bottles from expeditions years ago litter this wind-scoured place.

DAVID BREASHEARS: Highest junkyard in the world. Anything you need, we have it. Tent poles, spare oxygen, tent stakes, and the odd corpse!

NARRATOR: When you die at 26,000 feet, no one has the energy to carry your corpse off the mountain. The climbers are slowly deteriorating, their bodies literally consuming themselves for energy. Simple tasks take longer to perform, and precious energy is burned just gasping for air. While most climbers are resting, David, Ed, and Carter endure another round of psychometric tests.

HOWARD DONNER: Old houses are more difficult to maintain, but worth the extra time and effort.

ED VIESTURS: Old houses are more difficult to maintain, but are worth the extra effort.

HOWARD DONNER: I'd lived by the river for 20 years, and only twice before in all those years has it been this high.

DAVE CARTER: Ed lived by the river for 20 years, and this was the—the first time it had been this high. Over. Oh, boy...

HOWARD DONNER: The wildflowers bloomed in profusion in the high meadows in August.

DAVID BREASHEARS: The wildflowers broomed in profusion in the high meadows in August.

HOWARD DONNER: OK, Carter. Sounds good. We'll be with you in a minute.

DAVE CARTER: Sounds good, Doc. (coughs)

NARRATOR: David radios Ed, who is in a nearby tent. The scene feels all too familiar.

DAVID BREASHEARS: Ed?

ED VIESTURS: I just tuned in. What's going on?

DAVID BREASHEARS: I'm having serious doubts about going up today. Something about climbing with all these people. It's got me bothered in the way that a few days last year, it had me bothered. What do you think?

ED VIESTURS: It does concern me that there's a lot of relatively inexperienced people. Hopefully, nobody is going to get in trouble. If they do, of course, the more experienced people always have to help out.

DAVID BREASHEARS: I mean, who looks after who up there, you know? How do you sort that out? I mean, I don't like to be around people staggering around like that. I don't know. I'd like to see this day just kind of sort itself out without me in it.

NARRATOR: It is a brief moment of doubt. But in the end, David decides to go up, knowing he can always turn around. Five hours later, the climbers prepare for their departure. At this altitude, loading a pack and putting on crampons will take two hours. Each climber carries two bottles of oxygen. They leave at 10:00 p.m.

PETER HACKETT: When one considers that condition that a climber is in on the South Col on summit day, it's really amazing that they can reach the summit at all. First of all, there hasn't been sleep for usually a couple of nights. There hasn't been enough to eat or drink. Even if they've been on oxygen, it's still been very uncomfortable to breathe. The mucous membranes are all dried out. There is always a sore throat. There is always a cough. There is often a headache. And it takes a tremendous amount of will to keep going under these conditions.

NARRATOR: At 5:30 in the morning and 300 feet below the summit, David calls down to Howard.

DAVID BREASHEARS: We've been climbing like crazy. We're on the South Summit—28,700 feet.

HOWARD DONNER: It's unbelievable! You climbed in the middle of the night and you're standing up there in the early morning.

NARRATOR: They sit down to rest. Ten feet in front of them lies the body of Rob Hall, one of the expedition leaders who died in 1996. David points to where Rob is buried under wind-driven snow.

GUY COTTER: How far buried do you think he is? Five feet?

DAVID BREASHEARS: It could be five or six feet. It's a lot.

GUY COTTER: Right. Yeah. Rest in peace.

NARRATOR: They have only 300 vertical feet to go, but two hours of climbing. They traverse a knife edge ridge which drops off 8,000 feet on both sides. David climbs in front. They reach the Hillary Step, a 40-foot wall of exposed rock. This is the most technical terrain on the summit day. Climbers maneuver up the cracks and over the rocky outcrop while clipped into the fixed ropes. Carter hoists himself up. Only one climber can ascend at a time. This is where bottlenecks occur. They silently pass by the body of a climber from an earlier expedition who died here on the ropes.

PETER HACKETT: The breathing becomes unbelievably difficult. You feel like you are one huge lung. The heart rate at rest becomes higher and higher. The maximum heart rate becomes lower and lower, and as you go higher, those two get closer and closer together. And of course, when your resting heart rate equals your maximum heart rate, all you can do is rest. You can't do any more physical work.

NARRATOR: They have climbed for nine hours. Jangbu raises the Tibetan flag on the summit. David is sitting on the top. Ed is taking the last steps up with Carter just behind.

DAVID BREASHEARS: Base Camp. Base Camp. This is David. Do you read me?

HOWARD DONNER: David, we read you loud and clear. Where are you? Over.

DAVID BREASHEARS: Howard. I'm on top of the world! We made it. I'm on the summit of Mount Everest—29,028 feet. I am here with David Carter, Ed Viesturs. I can see everywhere. It's just so beautiful. I'm not going to be able to stand here very long.

NARRATOR: David Breashears has reached the summit of Mount Everest for the fourth time. Ed Viesturs has now become the first non-Sherpa to climb Everest five times and return. Rob Hall's fifth summit last year was tragically his last. Carter has lost his voice and will be unable to world's highest psychometric tests.

HOWARD DONNER: Mike walked around the block three times before he had the nerve to knock on Carol's door.

DAVID BREASHEARS: Mike walked around the block three times before he had the nerve to walk on Carol's door.

HOWARD DONNER: Excellent, David. Do you have any oximetry on the summit? Over.

DAVID BREASHEARS: I'm at 78, sitting on top of Everest.

NARRATOR: At 78, David's blood oxygen saturation is good for a climber breathing supplemental oxygen. Climbers consume bottled oxygen at a flow of two liters per minute on a summit day. With his mask off for a few minutes, David's respiratory rate increases significantly.

HOWARD DONNER: David, what's it like climbing back in the same area that you were in last year? Over.

DAVID BREASHEARS: Well, the bodies that were there last year were covered. But unfortunately, we did pass one body right on the fixed ropes. It only makes me question my sanity, and why I climbed this mountain again, because it is dangerous and cold.

NARRATOR: Ed takes his final psychometric test on Everest.

HOWARD DONNER: The man who was an engineer came to the store where Alice worked to buy pastries. Who bought pastries?

ED VIESTURS: Uh, the engineer, Jack, the guy. (laughter)

HOWARD DONNER: Where was Alice?

ED VIESTURS: In the store.

HOWARD DONNER: Ed, I know you want to get moving again. Let us know how you're doing, how you're feeling. Over.

ED VIESTURS: I feel fine. It's getting kind of cold. The descent is quite arduous. You're physically spent. You have to think about what you're doing. You can't just stagger and slug your way down. A lot of accidents in mountaineering occur on the descent, and it's because people get to the summit and they totally let down their guard, and they've used all of their energy just to get to the top.

NARRATOR: It takes five hours to climb down to Camp VI. In the safety of his tent, David reveals to Howard that he had a difficult climb to the summit.

DAVID BREASHEARS: Howard, this is South Col.

HOWARD DONNER: Hey, David. This is Howard. Go ahead.

DAVID BREASHEARS: This morning, I drank about a quart of Kool-Aid. Then, I stopped and I threw up about six times. I thought I would have to come down, but I didn't want to leave the team behind because it was just—I kept thinking I'd feel better. I had the worst trip down from the South Summit I've ever had. Over.

HOWARD DONNER: I got that, David. How's everybody doing? Over.

DAVID BREASHEARS: We've got to get these guys out of here. He's a little sick.

NARRATOR: David Carter's condition has worsened. Despite his own illness, David Breashears picks up the camera to shoot Ed taking care of Carter.

DAVID BREASHEARS: Tell me what's up?

ED VIESTURS: He's at 93 and 133. So, your pulse ox is really good. Your throat feels real constricted?

DAVE CARTER: (whispers) Yes.

ED VIESTURS: OK. He's on a four-liter flow. David started having problems coming down on the South Summit. He couldn't catch his breath, so we called the Doc at Base Camp, told him what was going on, and he doesn't know whether it's something like pulmonary edema, or possibly the fact that David was having some lung infection earlier on that he's been fighting, and whether the altitude just exacerbated that. So, I think the best option, if he can handle it, is to get him down to Camp II. The lower we get him, the better.

DAVE CARTER: What about oxygen at Camp II?

ED VIESTURS: Yeah, there's a bottle.

NARRATOR: They have just climbed to 29,029 feet, the summit of Everest, an exhausting accomplishment. Now, they will try to descend 5,000 more feet to get Carter to a safer altitude.

DAVID BREASHEARS: Hey, David? Good luck, man. Sorry you had to get sick like this.

NARRATOR: David Breashears stays at Camp VI to rest, as Ed accompanies Carter.

ED VIESTURS: He would go 10 or 20 feet, and then we'd stop for five minutes. You know, he had to catch his breath, he'd have to take his mask off. He was overheating, desperately trying to gain control of his breathing. I thought we could get to Camp II, but as it turned out, it took us a long time. It took four and half hours to get down to Camp III. So, it was about 7:00 p.m. then, and we got into the tent. And that's when it started to get a little hairy.

NARRATOR: After hours of labored breathing, Carter gains enough strength to get on the radio.

HOWARD DONNER: Carter, my man, how are you doing?

DAVE CARTER: Still alive. It's been a hell of a day.

HOWARD DONNER: Tell me. This is very important, Carter. I need to get a feeling for whether you feel like your lungs are full of fluid. Do you feel like it's difficult to get air? Do you feel really short of breath? Or do you feel more like it's wheezy in your upper airway, like you have asthma? Over.

DAVE CARTER: Oh...I really don't feel like I have anything in my lungs. It—It feels like my throat has closed up on me. Or I have asthma, something like that. Last night, I coughed up a lot of green, hard chunks. A couple of them had blood. Over.

NARRATOR: Carter seems to be improving. But two hours later—a desperate call from Ed.

ED VIESTURS: I need Howard. I need Howard. Please try to get him.

HOWARD DONNER: What's going on, Ed?

ED VIESTURS: David's dying! It's like his throat's obstructed.

HOWARD DONNER: Ed, I'm going to keep talking. You don't have to respond. See if you can do a Heimlich. Get him to expel whatever is obstructing. Over. OK, Ed, listen to me. I'm not sure where you're at. If it's an obvious obstruction, you can push it out with a Heimlich. Do that. If it just seems like Carter's airway is closing and you need to breathe for him, go ahead and start mouth to mouth ventilation. Over.

ED VIESTURS: OK, hang on. I did a half a dozen Heimlichs and it seemed to help.

HOWARD DONNER: Tell me what Carter is doing now. What is his respiratory status? Over.

ED VIESTURS: He's sitting up. We did some more Heimlichs. It seems like he's calming down a little bit. Hang on.

HOWARD DONNER: OK. What's very important, Carter, for you, is I want you to take nice, easy, slow, deep breaths. Breathing quickly right now won't help you, Carter, and I know this is really scary. You're going to do fine, but I need you to breathe deep. In and out, and in and out. Slowly. And know that Ed and the rest of us are going to take care of you. Over.

ED VIESTURS: David was desperately gasping for air. I wasn't sure he was going to make it through the night. I mean, he had his doubts, and it's a scary situation to be up there all alone. I mean, thinking that you know, here this guy might die on you.

DAVID BREASHEARS: Here we go. It looks like we have a record level. That light came on. It's plugged in? OK, David. What's going on?

DAVE CARTER: It's been a long—(sneezes twice)—It's been a really long couple of days for me. I've been very sick coming down. I've been totally exhausted. I'm having problems getting a full breath. My throat feels like I'm breathing through a straw right now. This is God's gift up here. That was the first time in my life when I literally thought I was going to die. I still to this point have not even thought of summiting. I just want to get down the mountain. Choking to death at 23,000 feet—The first thing that went through my mind was how isolated I am, and I'm not going to be rushed to the hospital and revived. I knew that when I was choking, there was just two people there. It was myself and Ed, and it was frightening. I don't want to die. I don't want to die in the mountains. I don't want to die young. But since I've survived it, it's a big part of my life now.

TONE TEST: (tones can be heard)

DAVE CARTER: Eleven.

NARRATOR: Ten days after coming off Everest, the climbers return to Seattle for a final session of testing. The scientists have now had a chance to analyze the data.

PETER HACKETT: The pulse oximetry data collected on this expedition showed, as expected, the decline in oxygen with high ascent to altitude. And David Carter in particular had lower blood oxygen levels, which seemed to go along with some of the problems he was having on the mountain. We need to do more careful analysis of the relationship of the pulse oximeter readings to the MRI scans.

NARRATOR: Dr. Hackett has looked closely at the MRI scans, searching for abnormalities. He discovers that exposure to extreme altitude can leave its mark on the human brain. Hackett addresses the climbers.

PETER HACKETT: And actually, the only abnormality we found was a very mild atrophy in the brain of Ed Viesturs, who was the one that has climbed many times to high altitude without supplemental oxygen. And what we'd like to do is follow him over a longer period of time to see if this is something that might actually progress with his high altitude career.

DAVE CARTER: (on video monitor) Ed lived by the river for 20 years, and this was the first time it had ever been this high. Over. (coughs)

DAVID BREASHEARS: Oh...

DAVE CARTER: Man...

DAVID BREASHEARS: You were feeling bad there.

GAIL ROSENBAUM: We have reviewed all the tests you see. And you see that there's a real difference in your performance at high altitude. At the higher elevations, you're obviously in survival mode. From the numbers, we could see that your performance was deteriorating. And had we had those numbers available, we would have probably suggested that you might not want to continue.

DAVE CARTER: I'm shocked. And I realize now how sick I was. And I—You just—You don't—It's just a haze up there.

DAVID BREASHEARS: You can't tell up there.

DAVE CARTER: No. No.

DAVID BREASHEARS: We were all just getting by.

DAVE CARTER: Yeah.

HOWARD DONNER: I'm looking at David for the first time at Camp IV, and typically, you know, I'm talking to him on the radio. And in fact, you saw when he was coughing, he had the microphone off. So, I'm hearing his responses. I'm not watching him cough or seeing how awful he looks.

GAIL ROSENBAUM: The question then, we ask is, what happens if you're in an emergency situation, are you able to think quickly, are you able to think clearly about what you need to do to survive and get down?

PETER HACKETT: You can see how, in his condition, he could have not tied his rope correctly, not tied into his harness correctly, not clipped in the anchor correctly. (laughter)

DAVE CARTER: I love this mountain. I have learned a lot. You know, I summited, but I still don't even think about the summit. I'm still thinking about that night at Camp III, being near death, possibly dying. When I passed by the last ladder of the Icefall, I knew that I had survived Mount Everest.

CAPTION: In the spring of 1997, 86 climbers reached the summit of Mount Everest. Eight climbers died.

HOWARD DONNER: David, we're curious, now that you've been to the top, do you think this was your last trip up this mountain? Over.

DAVE CARTER: Well, it's the hardest day I've ever had on the mountain. And I have no intention of every going to the top of Everest again. And I need lots of people to prevent me from changing my mind.

Take the test yourself. See the 360 views from the top. Return to Everest, and experience everything with the extreme altitude. Start climbing, at www.pbs.org.

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This is PBS. (read less)

The human body is highly adaptable to change. It adjusts when you vigorously exercise, move in and out of different temperatures, or face stressful situations. But what about when your body is pushed to extremes, like those of climbers attempting to summit Mt. Everest, which rises 8,848 m (29,028 ft) above sea level? In this environment, climbers confront an atmosphere of one-third less oxygen than at sea level and life-threatening, frigid temperatures. This episode of NOVA follows a doctor at Everest's Base Camp who tracks and analyzes the effects of this harsh environment on climbers' bodies and cognitive functions. The data reveal to what extent these climbers' bodies can adapt and survive at high altitudes.

TRANSCRIPT

"Everest: The Death Zone"

PBS Airdate: February 24, 1998
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During the following program, look for NOVA's Web markers which lead you to more information at our Web site.

ANNOUNCER: Tonight on NOVA, Everest. In 1996, eight died in a single day. N...

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