In reply to Trangia: First significant, in fact first actual peak was the Weisshorn, setting off for the hut at mid-day, having arrived after driving from the UK at midnight the evening before. At 4200m I felt like death warmed-up, but with less motivation or energy. Amazingly I actually made it to the top.
Naively I assumed that the people I was with knew what they were doing. It was only later that I realised what a f**** stupid approach it was.
I make much better informed alpine climbing mistakes these days.