Man is that ever true, my wife often gets on me for farming in the heat. But exactly as John so eloquently said if I don’t expose myself to it and develop a tolerance I simply cannot make two or three days standing out on the gravel at some range teaching students not to shoot themselves. The only way I know to build up that immunity is to submit myself to the heat! Well and hydrate of course. Foot note: Qore technologies makes a great ice pack that fits under our body armor and contours to the body. John, it is only good for about four hours per ice pak. Then you swap in your backup. I have never thought about wearing it at the race track? I can post pix if any one is interested. It has its own skimpy carrier that can be worn under anything. It is a game changer for those of us that hang out all day in battle rattle!