CoolerDog Refill Ice Sheets Help your dog stay cooler and more comfortable even longer. The CoolerDog Refill Ice Sheet is a direct fit replacement for the Cooler Dog Hydro Cooling Mat. Each sheet provides approximately 2-3 hours of cooling comfort to your furry friend at room temperature. Cooling times will decrease in warmer weather, or in direct sunlight. Once the sheet is liquid again, just pop it in the freezer and replace with a frozen one to keep your dog cool all day long! Each sheet is engineered for numerous freeze thaw cycles, so you can be sure the CoolerDog Ice Sheet will be ready to go when your dog needs it most.