What makes the death zone on mount Everest so challenging?

Answer 1

The region above 25,000 feet (7,600 meters) is called the death zone. The reason for this name is because nothing lives at that altitude or above and no human can survive long there due to the lack of oxygen in the thin air. Climbers are very vulnerable to altitude sickness once they climb into the death zone. They cannot escape the potentially deadly effects of oxygen deprivation, although they can help themselves by staying in the Death Zone for as minimum time as possible before the thin air eventually wears the body down.