The HyperKewl evaporative cooling material is a unique fabric that absorbs and slowly releases water through evaporation. We look at this process as "super-charging" the bodies natural cooling process, thereby protecting the wearer against heat stress. While other technologies are effective for pre and post cooling while you compete, HyperKewl works to cool you during the competition or strenuous activity. Simply soak in water for 1-2 minutes, gently squeeze out excess water and enjoy the cooling effect for up to 5 hours dependent on ambient conditions. Simple, fast and easy to use!