Chill-Its 6230 L/XL Khaki Standard Phase Change Cooling Vest with PacksErgodyne Ei 12010 The Chill Its 6230 Standard Phase Change Cooling Vest keeps workers cooler, safer and more productive. The phase change cooling material maintains a 64 F (18 C) temperature for up to 4 hours when activated. The vest is made of a comfortable cotton blend fabric with adjustable hook and loop closures at the shoulders and waist to provide a customized comfortable fit. SIZING The cooling vest comes in two sizes ranging from S M (32in