Since 1997, Glacier Tek has been making high-tech garments that help defend the wearer from heat stress in extreme environments. Our first product, the Original Cool Vest, was among the earliest completely self-contained body cooling vests available on the market. Glacier Tek cooling vests feature PureTemp phase change material, a biobased technology designed to absorb heat generated by the wearer. Glacier Tek vests maintain a comfortable 59 degrees for up to 2.5 hours, even in the most extreme heat, and never over-cool. Our vests offer better safety and cooling duration than that of evaporative, ice or gel-cooled vests. Every Glacier Tek vest includes a set of cooling packs powered by PureTemp, a safe and effective biobased material that carries the USDA Certified BioPreferred® label.