Chiller is an endothermic chemical designed to freeze a quantity of water for later use as coolant. Sold in 500g packets, it is designed to be mixed with 5l of water. The water will freeze solid in a few minutes. When mixed with larger quantities of water, the reaction will cool the water, depending upon volume.
Once the ice melts, the resulting water is no longer potable and should be disposed of. It can be re-used with additional packets of Chiller to create more ice.