Long Lasting Relief When to use Recommended for muscular pain, strains and joint stiffness. Can be used for back, hip, thigh, calf, arm, neck and shoulder pain. How it works Therapeutic heat from the Deep Heat Pain Relief Heat Patch provides targeted pain relief right where you need it. Plus, penetrating heat helps relax stiff, sore, aching muscles and joints helping to restore movement. How to use Use on clean, dry skin. Tear open the plastic packet, remove the protective film from patch and apply to affected area. The patch activates within 1 minute and will heat up within 5 minutes providing penetrating warmth for 8 hours. Once removed it can continue to provide pain relief for a further 8 hours. Delicate or aging skin: apply adhesive side of patch to clothing. Read the label.