At age 67 I can identify with the heat, now. I worked in a dry cleaners for 28 years and the first two years after retirement I had no problems in the car. Seems this year I have become acclimated to the air conditioning and really suffered at Road Atlanta in May. Hence, a new cool shirt with a leftover medical cooler. Much less sweating, comfortable in the car for the complete 45 minute ProIt, and no leg cramps after the race. 100% endorsement for the cool shirt. Chuck