Handmade Corn Bag Heat Pack. Made from 100% twill that can be heated in the microwave and also be put in the freezer. This is to soothe achy muscles or to warm you up on a cold day. Standard size is approx. 7"x10" The name of this pattern is Dora The Explorer. All of our corn bags are made with field corn which keep heat in a lot longer than the rice packs do. All corn bags have a removable covers which are machine washable.