Racing in 100+ heat, any advice?

The biggest help you can have is the medium sized cooler full of ice water, and a towel.

Between rounds, open the cooler and cup your hands. Throw that cold ice water on your face and head a few times. Also, hold your arms over the cooler and rub the ice water on them. You would be amazed at how this helps bring down your body temp.

I also wet the towel and only half ring it out. I then put it around my neck before going to the staging lanes.