been in the high 90s here with very low humidity (think blast furnace) with no shade....got a few miles in last weekend.
I did put a 10mm shorter stem on the bike and went from 110mm to 100mm on the Deda Trantacinque stem. I love the fat bars (35mm tops down to the hoods with normal 31.5mm drops) as my gorilla hands fit nicely on them; oh and they cut some weight from the bike.... <sings "I'm a weight weenie">