It is used for hot or cold therapies. It can be heated in the microwave for 3 minutes and the heat lasts about 30 - 40 minutes. The great thing is that when you feel it cooling off all you need to do is wiggle it a bit and the heat comes right back. It is made with lots of natural ingredients such as chamomile, cinnamon, peppermint and rosemary among other. When heated it releases a very calming chamomile/peppermint scent. I am usually not one to like very scented products, but this one is not too heavy. When chilled in the freezer, the cold therapy lasts about 1 hour. It can also use be used to keep you warm during those crazy cold days we seem to be having. Another good thing about this product is that it's made in Canada. I can't seem to find them online but they are at the Home Show right now and their business card says they are located in Claremont. They have a great variety of patterns and they come in various shapes and sizes.