hematopoiesis. (physiology). The process by which the cellular elements of the blood are formed.ematopoiesis. (physiology). The process by which the cellular elements of the blood are formed.
This is why Everest climbers typically make several trips up and down the mountain to increasingly high elevation camps to acclimate their bodies to high altitude conditions. Other risks to Everest climbers include frostbite and hypothermia from the extreme temperatures, thrombosis or embolisms caused by thickening of blood in response to high altitude, extreme sunburn, and broken bones from falls.
In 2013, about 340 permits to climb Everest were granted. Since Tenzig and Hillary climbed in the 1950s, about 4,000 people had climbed Everest in the years leading up to 2013. That year, three climbers were attacked by a mob of 100 Sherpas at 21,000 feet altitude.