Ergodyne - EGO12002 Chill-Its 6235 Standard Phase Change Cooling Vest keeps workers cooler, safer and more productive, maintaining a 64-degree Fahrenheit (18-degree Celsius) temperature for up to 4 hours when activated. Pair with cooling charge packs (not included) that quickly recharge in 10 minutes and have patented honeycomb design to eliminate stiffness. Extended vest surface area enhances cooling power. Adjustable hook-and-loop closures at the shoulders and waist provide a customized, comfortable fit. This body cooling vest is made of a comfortable, cotton-blend fabric. It delivers instant cooling relief for anyone working or playing outside or indoors in warm temperatures where heat-related illnesses are possible. This size fits 32" to 40" chests.