The route to the summit of Everest involves the arduous process of setting up a series of four camps containing supplies, shelter and oxygen, usually performed be the Sherpas. To acclimatise to the thin air, climbers go through a process of making their way up to each camp and then heading back down again to spend the night, allowing the body to adjust. Eventually spending nights at the higher camps.

The final quest for the summit is taken from Camp three into what is called the ‘Death Zone’. An altitude so high that humans cannot survive for very long. In the early hours of the morning in calm weather, climbers head for the summit hoping to arrive around sunrise. There needs to be enough time to get down to Camp three before the strong cold winds pick up in the afternoon. Starting early also avoids the long queues that form on the final route. Climbers can be stuck for hours waiting and can often miss their attempt with the real possibility of running out of oxygen or time to descend.

The video here is the route Sue took via the North East Ridge showing the camps.