One of the riders I have been coaching for several years is training for the SCNCA time trial championship. Last year when he raced there, it was an unusually warm day and the heat really got to him. Steve lives in San Diego, where the weather is quite temperate, but the race is in Lake Los Angeles where it gets MUCH warmer in May. In fact the lake Los Angeles area is typically at least 10-15 degrees warmer in May than coastal San Diego Where Steve lives. So 2 weeks ago Steve started working to acclimitize to the heat by working out in his sun room twice a week. He set up the trainer, turns on the heater and just goes for it. Heat accilimitization starts to occur in is little as 3 days, and full accilimitization can be achieved in as little as 2 weeks. Acclimitiazation adaptations simply allow the body to stay a little cooler AND operate at a higher level when hot. These adaptations include increased blood volume, increased skin blood flow increased sweat rate, and changes in the sweat itself.Steve is off to race in the 50+ category. Good luck steve, those hot trainer sessions should pay off!