In another lifetime I did sports car racing. Drag racers shut the fuck right up, you are in that oven for what 10 minutes tops. Try an hour.
I remember when I bought my first "cool shirt". It was a t-shirt that had tubes in it that water would run through. It had a little cooler and you filled that with ice and water. First time I hit the switch I thought it was dumping ice water all over me, it was so cold. Then no it was just the water running through the suit. My cooler would last about 1 race. By then end of the session the water would be warm to the touch. One thing for sure it did make your mind "more fresh". You loose something when you get that hot and sweaty.
Basically long johns, a head sock, and gloves head to toe.