The pleasantly soft fleece heating pad provides a warm surface for your dog, cat, or small animal to rest on and can also be used specifically as a hot water bottle. Simply remove the fleece cover and place the pad in the microwave for the appropriate time. After that, put the fleece cover back over the pad - now it will keep your pet warm for up to 8 hours. You can also use the pad as a cooling pad by simply placing it in the freezer for a while - no water filling is required.