We recently completed testing with SGS on the cooling capacity of our HyperKewl fabric. The results were better than expected. HyperKewl PLUS fabric, when quilted as the middle layer between a waterproof nylon and a breathable outer nylon, generates an average 0.231 W/cm2. In terms of the cooling capacity of a standard vest (6529), that equates to up to 2287 BTU/hr of cooling from HyperKewl PLUS. Considering that a small air conditioner generates up to 6000 BTU/hr, the capacity of HyperKewl PLUS to cool you down is very impressive.