What, exactly, happens to the body of the climbers in “The Death Zone” (i.e. on Mount Everest) that causes their death?
Some of the biggest factors are called HACE and HAPE; high-altitude cerebral edema and high-altitude pulmonary edema. Both of them involve fluid accumulating in a place where it shouldn’t due to the body’s stress at high altitudes – for HACE, fluid is accumulating in the brain, causing confusion and disorientation, while for HAPE, it’s accumulating in the lungs causing shortness of breath. And when you’re up on a mountain fighting exhaustion, weather, and the climb itself, either of those can prove quickly fatal. I believe that HAPE-related deaths are one of the most common, specifically, at high altitude.
And the scary thing about HACE and HAPE is that they can seemingly happen to anyone, anytime at high altitude. Being physically fit and acclimating to altitude slowly seem to reduce the chances, but even some of the most fit and prepared mountain climbers have died due to those conditions. If you’ve ever seen the movie *Everest* or read *Into Thin Air,* about the 1996 disaster on Everest, they note that Gary Ball, one of the founders of the Adventure Consultants company, died a few years before that disaster due to HAPE – and he was one of the most physically fit and well-prepared mountaineers in the world. Some of the guides and mountaineers who died on Everest that day were showing possible signs of HACE, possibly impacting their abilities to make decisions and move effectively.
Falling, hypothermia, hypoxia, high-altitude cerebral edema, high altitude pulmonary edema…take your pick. In the death zone specifically, hypoxia (lack of oxygen) and its effects are common causes of death. Above 8000 meters, there’s simply not enough oxygen for humans to survive. Climbers in the death zone without supplemental bottled oxygen are slowly suffocating every minute they spend at this extreme altitude.
The air is thinner the higher you go. Above a certain altitude, the air is so thin that each breath of air provides less oxygen than the body needs to survive. Most hikers up Everest bring oxygen tanks to breathe from for that portion of the mountain, but if they don’t, their body will gradually use up the oxygen in their blood. Eventually, the cells of the body will die after being deprived of oxygen for too long, and while the body will attempt to prioritize oxygen to the brain, eventually the brain or some other vital organ will have too little oxygen for too long and begin to die off, leading to the person dying.
There is not enough oxygen in the air at that altitude to keep a human alive. Climbers carry oxygen in bottles, to supplement the air they breathe. Without enough bottled oxygen, they suffocate.