Cool Shirt Active Aqua Vests can be used two ways: as a constant connection to a cooling system for ongoing cooling during strenuous activity, or on-demand.  Suitable for breaks during sports or when working in hot conditions.  Also suitable for when constant movement is not required but continual cooling is.  How do they work? They circulate cold water through 50 ft. of medical-grade capillary tubing securely stitched to the front and back of the vests. Spring-loaded connectors easily attach the vests' tubing to a portable or stationary cooling system to cool body temperature.  PLEASE NOTE: ALL COOLSHIRT ITEMS ARE PURCHASED SEPARATELY.  MAKE SURE TO ORDER ALL NESSESSARY PARTS FOR THE SYSTEM TO WORK PROPERLY. Cool Shirt Systems and hoses sold separately. Cool Shirt Systems - Active Aqua Vest