Just hook it up and your petʹs water will stay open all winter, even in the coldest temperatures. It is perfect for the outdoor dog or several outdoor cats. Thermistors located inside the Thermal-Bowl automatically adjust to the fluctuating temperatures which makes certain the unit stays working at its best and therefore cannot freeze over. When the temperature gets that cold, the Thermal-Bowl will begin warming after it has been plugged in to a power outlet. Never submerge your Thermal-Bowl in water or other liquids to clean it. You can wipe it from inside and out with damp cloth and a mild detergent can be used to clean. But be sure all detergent has been removed before watering your pets.