This is the vest that employs evaporative cooling to keep its wearer comfortable for hours even in oppressive heat. Exclusively available from Hammacher Schlemmer, this vest features moisture absorbing crystals strategically placed in the front and back that soak up many times their volume when the garment is submerged in water. This moisture is then released slowly through evaporation, creating a natural cooling effect that can help stabilize your core temperature and prevent heat stress. The vest can even be chilled or frozen after activation to enhance its cooling ability. Ideal for use before, during, or after exercise, the vest's technical fabric fits snugly to stay in contact with your body's core, yet stretches to allow freedom of movement. Khaki. Unisex sizes M (40" chest), L (44"), XL (48") and XXL (52"). (1 lb.)