Heat Therapy Pain Relief Effectively: Heat therapy for temporary relief of minor muscular and joint aches and pains associated with overexertion, strains, sprains arthritis, and menstrual cramps. Stimulates the nerve endings in the skin to provide feelings of warmth and dull the sense of pain. Heating Instantly, Holds Heat 12-18 Hours: heat therapy patches for pain relief contains high-purity iron powder and activated carbon, they don't take long time to heat up and stays heated for quite awhile. Taking the disposable heating pad out the bag, contact the air properly, and then stick it on the clothes of all parts of the body. Please don't exposed to the air for too long after open the bag. Better not Adhere to Skin: In order not to burn your skin, we recommend that you wear the heat patches for back pain relief over your clothes, not your skin. You can stick it on the clothes of various parts of your body. It is very sticky and not easy to move or drop, you can rest assured of sports or activities. Body warmer: During cold winter, you can always carry the heat sticker outdoors, office, or anywhere. Very convenient to carry in your pocket or bag. It can be pasted anywhere on your body when you feel cold, the heat patches for pain relief are your movable radiator or central air conditioner.