Isotherm is a revolutionary technology that offers more cooling, lasts longer and provides comfort to your workers. Tests have proven that the Isotherm cool vest stays within the human “comfort zone” much longer than any other product. Unlike ice or gel packs that quickly lose their cooling, Isotherm’s unique phase-change technology maintains a constant, pre-set temperature that will provide hours of effective cooling to the user. The cool packs within the vests can be recharged thousands of times, providing hours of safe, controlled body temperature management. No waiting… no downtime… Simply submerge Isotherm Cool Packs in the cooler with ice water and they are fully energized in 20 minutes. Isotherm outperforms the competition, providing up to four hours of cooling in 90°F ambient temperatures.