Day 3 Kili Ascent - Monday

Day 3 climbing to Mawenzi Tarn Camp at 4,280m altitude, then a practice high altitude climb up to the Mawenzi summit - and then back down again through the scree in an hour! :-/
Some team members have started to feel the affects of altitude sickness. In fact at present I appear to be the only one who isn't suffering at all although the lack of sleep at night is starting to get me down. I'm exhausted and I'm worried it will hit me all at once at some point.