Heat-activated PhaseCore® cooling products absorb heat and provide a long-lasting cooling effect that will not overcool the body. The gentle cooling effect of PhaseCore will help to increase productivity while reducing heat-related illnesses. PhaseCore is a phase change material (PCM) that products a cooling effect by transforming from a solid state to a liquid state when the surrounding temperature rises above its activation point. PhaseCore elements are available in a variety of activation points with PhaseCore 28 and PhaseCore 32 designed for personal cooling. PhaseCore cooling vests can be worn while suiting up, while down range, and during rehabilitation to avoid extreme temperature changes. PhaseCore elements are made of a non-toxic, non-flammable salt mixture and sealed inside a thermal wrapper. PhaseCore elements are not effected by humidity and react only to direct heat. PhaseCore is simple, safe, and reusable.