Reusable Hot and Cold Back Pad retains its warmth for up to two hours, easing muscles into more relaxed states.. Direct applications of heat can help alleviate muscular pain and provide relief from pain or stiffness caused by tense or sore muscles. The versatile back pad accommodates to your needs by providing instant heat when you need it. To use it as a cold compress, place the Palm Nrg pad in the refrigerator for 2-3 hours until thoroughly chilled. It can then be applied to painful, swollen, or injured areas throughout the body. This pad is designed to fit perfectly along your body's contours, regardless of your position. It is also perfect for travel--you can take it with you anywhere you go! To reuse after heating, wrap the pad around a cloth and submerge in a pot of boiling water. The pad will turn clear once all crystals are dissolved. This indicates that it is ready to be taken out of the water and cooled. Once cooled, it's ready to be used again. After use as a cold compress, chill the pad in the refrigerator until ready for use again. Do not place the pad in the freezer.