HotPak Huggies are microwaveable heating pads or hot packs and cold packs or ice packs that are in the shape of animals, birds, reptiles and bugs. They are made at our factory in Pittsburgh, PA. They are filled with a non-toxic, water-based gel that can be used hot or cold. Pop them in the microwave. The large ones stay warm for over 6 hours, all night long under covers and the small ones stay warm for over 3 hours, over 6 hours under covers or inside a jacket. Use them for aches and pains, shoulder pain, back pain, neck pain, cramps. Use them as a warmer on cold days and nights. I always say that they are good for body aches and pains but they are really good for the heart and soul. Who can resist a warm hug!