The world's tallest mountains like Mount Everest and K2 have a 'death zone' — here's a first-hand account of what it's like

The "Death Zone" is a region near the top of world's tallest mountains that earns the name because humans aren't meant to survive there. There isn't enough oxygen in the Death Zone for the human body to function normally. Digestion can begin to shut down and some people have adrenal failure.