Litespeed,

Water, water, water!!! I ride in the Phoenix/Scottsdale area with temps of 100 to 110 degree or more. First, I try not to ride during the high temps (mid to late afternoons). Second, I drink like fish. Third, find a speed and pace that is comfortable, do not try and push it, steady as you go! Fourth, you need to build up to it. Meaning if you try and go out and ride in 100 degree temps, without gradually letting your body get used to the increasing temps and the effects it has on is no good.