Every year a city pops up out of nowhere at the base of the world's biggest summit. A mini-ecosystem out of the rocks covered in ice, in a place generally inconsistent with living.
It can take weeks just to reach base camp, let alone starting off for the summit. Those who do go up often only get one or two shots to reach the top before conditions turn.
Everest can only be climbed at the right time of year, when the weather conditions allow it.