The highest mountains in the world, like Mount Everest and K2, have a "death zone" – here's a first-hand account of what it is.

• Vanessa O 'Brien is an expert mountaineer and the fastest woman to climb the highest peak of all continents. She is also the first American and British woman to climb K2, the second highest mountain in the world.
• O & # 39; Brien explains what we felt in the "Zone of Death", 26,000 feet of altitude.
• The human body can not function normally in the Death Zone because there is not enough oxygen at this altitude. Digestion may begin to go away and some people suffer from adrenal insufficiency.
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Here is a transcript of the video.

26,000 feet or 8,000 meters, they call the "zone of death". You know, the death zone is part of what's happening up in the mountains.

You must remember that a mountain at 8,000 meters altitude, 26,000 feet, is the top of the troposphere. So you hit the troposphere and the stratosphere, that's where planes fly.

You are so high. Humans are not supposed to survive there. So when you climb there, even if you are on oxygen, oxygen is not like oxygen in a hospital.

You have a two liter flow mixed with the ambient air, it is not pure oxygen. The low amount of oxygen we absorb only compensates for the level of stress and prevents any frostbite from reaching the extremities, or what we like to call "numbers". But this is by no means something that would protect us from something like the death zone.

In the "zone of death", really, the digestion begins to close, you will have adrenal insufficiency, there is not enough oxygen to prevent a cognitive failure.

You will have adrenal insufficiency, there is not enough oxygen to actually prevent cognitive failure. You know, the brain and the lungs only get the minimum they need.

I like to think of it as a real time bomb of what you really need, maybe 24 hours a day. Anything above that, you really risk going to a memorial at the foot of the mountain.

That's why on K2, I was worried about our team. The top of our team was 16 hours. You know, when I look at this 24-hour window, knowing we're going down at night, you know, it was 23 hours. I think it threaded a needle very, very tightly.

EDITOR'S NOTE: This video was published on October 9, 2017.

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