Anyone who has read Jon Krakauer's famous account of the 1996 Everest disaster, 'Into thin air', will remember the story of Beck Weathers: the gregarious Texan climber who went snow-blind in the Death Zone below the summit and who spent a night out in the open during a blizzard that took the lives of a dozen colleagues and friends. Even as he staggered back into Camp 4 the next morning, Beck's condition was such that the other survivors assumed he...