The neck ties contain polymer crystals which expand when wet and can hold up to 500 times their own weight in water – amazingly with no dripping! This cold water slowly evaporates from the surface of the necktie, drawing heat energy from the surface blood vessels in the skin as it goes. Cooled blood then circulates back through the body lowering the core temperature and the reducing the risk of heat stress. The Cool Strip helps reduce your body’s core temperature when working hard in hot conditions.