New data identifies two key risk factors for high-altitude pulmonary edema, a leading cause of death on the mountain.

Related stories The danger zone High-altitude psychosis generally occurs at heights of 7,000 meters or higher, though it can strike hikers trekking at lower altitudes. Once referred to as mountain ...

When climbing Mount Everest, everyone enters a very dangerous elevation zone where oxygen is very scarce. In this "danger zone," the human body burns more oxygen than it can take in from normal ...