The Chill-Its® 6220 Phase Change Cooling Vest Charge Packs keeps workers cooler, safer and more productive. This charge pack is compatible with the 6215, 6225, 6230 6235 cooling vests. The phase change cooling material maintains a 64° F (18° C) temperature for up to 4 hours when activated. HOW TO USE *** Phase Change Vests not included. *** There are many ways to activate your cooling vest. Simply place the two removable packs in a cooler of ice water for 10 minutes; freezer for 15 minutes; refrigerator for 25 minutes; or near an air conditioner for 1 to 2 hours. Then place the recharged cooling packs in the vest pockets for hours of cooling. HOW TO CLEAN The cooling pack should be washed by hand with a mild detergent and warm water. Dry with a paper towel or cloth. DO NOT machine wash or machine dry. The fabric vest carrier is machine washable with mild soap; hang dry. Cooling vests are perfect for anyone in need of instant cooling relief while working or playing outside or indoors in warm temperatures where heat-related illnesses like heat cramps, heat strokes, heat exhaustion, etc. are possible. Ideal for workers in pulp/paper, iron/steel, vulcanizing, foundries, etc. or for people running, biking, doing yard work, riding motorcycle and more! Also, ideal for those needing cooling relief but aren’t able to use an evaporative cooling option.