The Chill-Its 6715CT Hard Hat Cooling Pad straps into hard hats to deliver four hours of cooling relief. The low-profile and lightweight liner pad features advanced PVA (polyvinyl alcohol) cooling technology for instant cooling without bulk or slime, making it comfortable to wear under hard hats. This hard hat liner pad fits most hard hats and safety helmets, easily and securely attaching to the suspension with two hook and loop straps. Heat-related illness continuously ranks among the top causes of worksite accidents and fatalities. Evaporative cooling technologies such as PVA are a simple, effective and comfortable solution for heat stress prevention. Similar to how sweat cools the body, evaporative technologies use an external water source to draw heat away-helping to regulate body temperature while providing cool relief. When activated, this PVA cooling hard hat pad is comfortable and refreshing for even the hottest days of the year.