Mission Enduracool Performance Hat Cools Instantly When Wet to 20 below average body temperature Chemical-Free cooling. Lightweight, UPF 50 protection against the harmful rays of the sun Cooling zones in the sweat band and front panels regulate the evaporation of moisture for a prolonged cooling effect. The ultra wicking fabric pulls sweat from the body and encourages quick drying Proprietary fabric activates when you sweat during activity You can also activate the technology by wetting the hat before wear. Soak the hat in water, wring it out and snap in the air for instant cooling