Following is a transcript of the video. Vanessa O'Brien: 26,000 feet or 8,000 meters, they do call the "death zone." The death zone is, you know, a part of what happens at height in the mountain.

But if climbers want to summit Mount Everest, the tallest peak in the world at 29,029 feet (8,848 meters or 5.5 miles) above sea level, they have to brave what's known as "The Death Zone" - the ...