Why do Everest climbers climb high but sleep at lower camps?

Everest climbers follow the practice of "climb high, sleep low" to allow their bodies to acclimatize to the extreme altitudes of the mountain.1

As climbers ascend, the barometric pressure drops, leading to a decrease in the partial pressure of oxygen available in the air. This environment can cause altitude sickness, a condition resulting from oxygen deprivation in body tissues. By climbing to a higher elevation during the day to establish camps or transport supplies and then returning to a lower camp to sleep, climbers give their bodies the necessary time to adjust to the thinner air.2341

This process stimulates physiological changes, such as increased production of hemoglobin and red blood cells, which improve the body's ability to transport oxygen. Proper acclimatization is essential for safety, as it helps mitigate the risks of severe, potentially fatal conditions like high-altitude pulmonary edema (HAPE) and high-altitude cerebral edema (HACE).243