At 12.28 I completed my 250th lap, or 100 km in distance, and left the track. I had been having a number of problems since 10.30 or so: I had been violently sick a couple of times and couldn't keep any food down; because I couldn't take food I was really struggling to run at all and was having to walk; and as I walked I was getting really cold in the near freezing conditions. So I decided to cut my losses, get to 100 km and decide that was enough. As I sit here at Dave's at 3 am, having had a hot bath and some Weetabix, I have no doubts it was the right decision. There was no point at all walking round a track for another 11 and a half hours, probably risking hypothermia.
Thanks to everyone for all their messages of support, but especially to Dave, Lee, Hannah and Jamie who put up with some very cold conditions without the slightest moan. I'm huegly grateful to you.
I'm sure I will have a fuller report in due course. On the positive side at least it wasn't a DNF - it was just a bit less distance than I had hoped for.