I made this adorable boo boo bag using flannel (inside - to keep the heat in longer) and 100% cotton fabric on the outside. It can be used hot or cold. Filled with rice. Perfect for minor boo boos and excellent for headaches as a cold pack. A set of 2, one can be stored in the freezer, one can be used as a heat pad. Heat it in the microwave starting at 30 seconds and gradually increasing to 1 min. Make sure to test on your skin before giving them to a child. To use as an ice pack - keep it in the freezer in a freezer bag. The fabric is hot pink with leaf design. Perfect distraction for a hurt child. Each bag is about 4-1/4" sq. (about 10,7 cm). Cannot be washed. Please keep the bags from getting wet.