Overheating and heat-related illnesses are serious conditions that can happen to anyone at anytime regardless of temperature, activity, age or fitness level. Using only one cup of ice, Cool Pouch&Trade; cools the carotid arteries in the neck and provides an evaporative cooling system for your body to help relieve heat stress. Studies have shown that if this area is cooled, the wearer can achieve a higher level of performance with less perceived effort. coolpouch.com