Mean annual air temperature on Everest is –13°C at 7,000 metres elevation, and yet the ice in its highest glacier is only –3.3°C.
While acclimatising is more important, here's the training you should undertake to go mountain-climbing.
Meet the first team trying to understand the secrets of Mount Everest's glaciers.
They erupted for billions of years and make Earth's volcanoes look like molehills. Here's what we know and what we don't know about them.
Reports claim the feature has vanished – but then mountains are always changing shape.