January 17

I wake up below Mwenzi peak with a splitting headache, the kind that throbs of pain with every pulse. I have some tea and get up to pee, but end up puking out everything I’ve consumed in the past 24 hours en route. Apparently both the stomach and brain need oxygen to function properly. The hike is exceedingly painful, but visually spectacular. We head to Kibo camp at the base of the main peak across desert. I find it really strange how the climates are ordered on the ascent: plains then rainforest then brush, then desert then glaciers. Weird. Head to bed at 6:30pm to prepare for the 11pm wakeup call for the final ascent. 16,000 ft.