>General Running>More on the cold
I remember seeing a chart in RW that showed how much heat or cold slowed you down. Over 85 or under 25 the affect was drastic.
When I was training for the Blue Ridge Relay I had to run three legs at night. I could not believe how much it slowed me down and it just mentally seamed longer in distance at night. it took me 60 days to get my night times down.