" Experiments conducted in decompression chambers had by then demonstrated that a human plucked from sea level and dropped on the summit of Everest, where the air holds only a third as much oxygen, would lose consciousness within minutes and die soon thereafter. But a number of idealistic mountaineers continued to insist that a gifted athlete blessed with rare physiological attributes could, after a lengthy period of acclimatization, climb the peak without bottled oxygen. Taking this line of reasoning to its logical extreme, the purists argued that using gas was therefore cheating. "

― Jon Krakauer , Into Thin Air: A Personal Account of the Mount Everest Disaster