In order for a dog to stay cool in the hot weather, its natural undercoat needs to stay dry and allow for the air to circulate through it. Kool Koats are made from synthetic chamois material that holds cold water within the material without getting your dog’s natural coat wet, thereby allowing cool air to flow through the undercoat. Both the dog and the Kool Koats stay cool for hours. The Kool Koats material wets down in seconds, and remains soft and pliable as long as it is kept moist. Kool Koats dry flat when not in use and will last for years. And Kool Koats are machine washable!