Sadly I hated it. I've run in the snow before (it was snowing) but somehow the early start took all the fun out of running a 10K in the snow :-)
After that all day I've felt very tired, so I won't be doing it again.
But I've noticed this evening my tolerance has gone. I just react much more quickly to mild annoyances than I normally would or wish myself too. E.g. I've been reacting to things on facebook with long comments and as a result just burnt the family's supper - which my wife is at this minute taking care of because I can't cope with it. Fortunately I seem to be coping ok with not being ridiculously miserable about this failure.
It's not a big shock that being tired all day makes one irritable. But it is interesting to get an insight into how fragile everything is, even when you think your mind is working generally well.
Update, 21 March
Barry sent me a link to a paper this post reminded him of, writing: "From my experience, it is important to take tiredness and irritability seriously."
Psychosocial determinants of recovery in depression, Fava & Visani, Dialogues Clin Neurosci. 2008 December; 10(4): 461–472.
"The majority of residual symptoms were present also in the prodromal phase of illness. The most frequently reported symptoms involved anxiety and irritability."I had to google "prodromal". To save you the trouble, Wikipedia says "In medicine, a prodrome is an early symptom (or set of symptoms) that might indicate the start of a disease before specific symptoms occur."