Rev 'It. Liquid cooling vest as a pilot of body temperature rises fatigue begins cycling game, which ultimately affects control. The vest coolant helps by using Hyperkewl ™ technology, which works by absorbing and storing water, and then releasing it over time through the natural cooling evaporation process. Because the cooling is activated by airflow ventilation, the better the jacket properties, the more effective cooling properties than the vest will be. For best results - Coolant vest with heavily ventilated jacket. Cooling user instructions with hyperkewl ™ products before first use, please Dunk the product underwater, gently squeeze out excess water and allow the product dries completely. This is necessary for cooling matching fibers in the product. Please note, the product may feel 'winding' due to migration activation after the first one. This rinses away at the next watering.