The Chill-Its Lightweight Phase Change Cooling Vest keeps workers cooler, safer and more productive. Its phase change cooling packs maintain a 64 F / 18 C temperature for up to two hours when activated.The vest’s adjustable hook and loop closures around the waist provide a customized fit for different body types. The heavy-duty front zipper makes for easy on/off, while the two front zippered pockets can be used to store small accessories.*** Phase Change Cooling Packs not included. ***There are many ways to activate your cooling vest. Simply place the four removable packs in a cooler of ice water for 5 minutes; freezer for 8 minutes; refrigerator for 12 minutes; or near an air conditioner for 1 hour.HOW TO CLEANThe cooling pack should be washed by hand with a mild detergent and warm water. DO NOT machine wash or machine dry. The fabric vest is machine washable with mild soap.