"Despite the dangers of racing in the heat, the race must go on. You'll read many interviews where drivers and athletes claim the body acclimates itself to extreme conditions over time. But "acclimated" isn't necessarily a synonym for "unaffected" and just because you can withstand discomfort doesn't mean it's always good for you. The strain from extreme temperatures affects a driver's cognizance as much as their physical ability to perform. When you're behind the wheel of a 2,500 lb. stock car edging 200 mph or pushing 10/10 in your track build, you need your mental focus to be as sharp as possible, not only for your own safety and the safety of those around you, but to perform your best and shave a few seconds off your lap times."