Racing in 100+ heat, any advice?

1st year in SSS points series, really want to make every race, but here in Central Tx we're starting to get into the 100+ days with fairly high humidity. So far I've been able to use shade and fans to get the car cooled down enough in between rounds, but it's getting hotter out there! My wife and I (my pit crew) seem to be taking it worse than the car but we don't want to sit in the truck with the A/C running, we feel like that will make the heat worse when we go back out. I switched from a 1 piece to a 2 piece fire suit so I can take the jacket off and I'm now wearing shorts instead of jeans under the fire suit. I have a 12V fan attached to the roll cage that blows right in my face, but sometimes all it does is blow hot air on me. Late at night my glasses will fog up bad in the staging lanes(this track is right next to a river) so I use the fan to clear off the glasses, too.