Cura Heat Back and Shoulder Pain are small discreet rectangular heat packs that provide targeted, temporary 24 hour warming relief from minor muscular and joint aches and pains. Just open the Cura Heat sachet and apply to clothing or underwear where the heat radiates through to the source of pain, increasing circulation, decreasing stiffness and relaxing sore muscles. The Cura Heat Back and Shoulder Pain patch is fragrance free, non-medicinal and with a thin discreet design, they are ideal to use anywhere. This product should not be applied directly to the skin. Cura Heat Back and Shoulder Pain warms up gradually and reaches maximum heat within approximately 30 minutes. Cura-Heat Back and Shoulder Pain is air-activated.