Perfect! Well, that's got to be a positive, hasn't it? It doesn't help you get through the hot weather training, but at least things will be easier by race day.
I guess for now, all you can do it take it slow and drink lots.
I mean water!
For long runs, I run loops of between 3 and 5 miles, and leave a stash of water and snacks on the front drive, to be picked up as I pass.