Discreet Heating Patches works for up to 12 hours to soothe cramps and provide therapeutic heat, right where you need it most. Our easy-to-use therapeutic heating patches instantly warm to a comforting temperature to soothe cramps, increase blood flow, and relax muscles. Use on the lower abdomen to soothe cramps, or on the lower back to alleviate aches and pains related to menstruation. Adhere patch to the outside of your underwear for on-the-go wear. Pack of 3.