By most analyses, 40 to 45 percent of body heat is shed through head and neck. The Coolshirt HotHead System provides head cooling for those who want a small, lightweight system and don’t need body cooling. The kit includes a Coolshirt Kart Bag, which is powered by 12-volt hookup or an optional lithium-ion rechargeable battery kit, a 4-foot water supply hose with safety-pull release fittings, and a Coolshirt Cool-A-Clava. It’s perfect for open wheel racing, legend cars, HPDE participants, and sports car racers who want cooling, but don’t want to add much weight or amp draw to their vehicle. $439.