A couple of things I used to do to beat the heat would be wear a pair of cross-training shorts (built much like a swim suit) and a pair of shoes 1/2 size too big, loosely-tied. I could kick off my shoes and put on my racing pants just before the cars pulled out of the lanes, then step into the shoes without untying them. I kept a couple of washcloths in a cooler of icewater and wiped my face and neck down after a run, put one around your neck when heading back to the lanes. A folding sunscreen inside your windshield helps, as well as draping your jacket over your steering wheel. Keep both doors open if you don't have roll-down windows.