Mission Enduracool Lifestyle Hat Cools instantly when wet to 20 below average body temperature Chemical-free cooling; 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 Ultra-wicking fabric pulls sweat away from body and encourages quick drying Proprietary lightweight fabric activates when you sweat during activity Activate the technology by wetting the hat before wear; soak hat in water, wring out and snap in the air for instant cool