I've been reading about the Tour Down under and right now, they're riding a stage in temps of 41C- that's about 110f. Of course, it's a DRY heat. BUt then, so's hell!
The best thing to do is watch videos from last year's TDF or other races that took place during hot weather, like the NYC race, or the Tour De Suisse.
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You can catch more flies with honey than with vinegar. That's great...if you want to attract vermin.