Chill-Its 6230 Standard Phase Change Cooling Vest with two packs keeps workers cooler, safer and more productive, maintaining a 64-degree Fahrenheit (18-degree Celsius) temperature for up to 4 hours when activated. Cooling packs quickly recharge in 10 minutes in a cooler of ice water, 15 minutes in a freezer and 25 minutes in a refrigerator. Patented honeycomb, ice pack design eliminates stiffness for more flexibility while you work. 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 40" to 52" chests.