Keep your dog COOL by using this comfortable and easy to refill DRY® Cooling Vest. After activating the vest by filling it with fresh water, it will immediately start cooling up to 15˚C / 59˚F below ambient air temperature for one to three days. Thanks to the patented system, the vest will never become wet or damp during use. The cooling effect is the result of evaporation and is largely dependent on humidity and airflow. So, prevent your dog from developing heat stress! During and after a walk (in the sun) or whenever cooling is required.