What is the "death zone"?

The "death zone" refers to high-altitude areas above 8,000 meters (approximately 26,000 feet), such as the summit of Mount Everest, where oxygen levels are insufficient to sustain human life over extended periods. In the death zone, human bodies cannot acclimatize due to the lack of oxygen, and without supplemental oxygen, this can be fatal. The body will begin to deteriorate, and prolonged exposure will lead to death, even without other complications like avalanches or falls. This environment is so inhospitable that even theoretical ideas like placing a hotel at such altitudes are deemed impossible due to the fatal implications of prolonged exposure to such low oxygen levels 1.