The HealthSmart™ PolarMat™ Cooling Aid features unique thermal insulation that continuously cools you 3 to 5 degrees by drawing heat away from your body, providing a cooler night's sleep. Simply place on your bed, and the mat begins to work instantly. The mats are great for use on top of a pillow, and can be used in the home, office, or for traveling and outdoor activities. This mat requires no electricity or freezing, and has a non-slip surface so it stays in place. This 100% cotton gel pack can be washed by brush with water. Available in large, medium or small sizes.