thin air

At five miles above sea level, the oxygen in the air is so thin that even with supplemental oxygen tanks, climbers feel like they are

Oxygen masks on the aircraft will be dropped automatically if the cabin suddenly loses air pressure and helps passengers breathe in a few minutes.

Life on a height of 4,900 m forces Tibetans to evolve very quickly to survive.

Scientists have discovered two genes that help Tibetans survive in the thin atmosphere of the highest land on the planet.