Simply click the metal disc and the pad heats within seconds Heats up to 54deg for approx 20-30mins Perfect for a cold walk with the dog Sooth those aches and pains or take the edge off the winter chill Grab yourself a heated pad and sooth those latest sporting aches and pains or take the edge off the winter chill. How to Heat1. Flex metal disc back and forth until crystals form.2. Knead pad to soften.How to Prepare the Pad for Re-use1. Boil water in a pot.2. Place a cloth on the bottom of a pot.3. Place the pad on the cloth inside the pot and continue to boil water until all crystals are dissolved and the pad is completely clear.4. When the pad is completely clear take it out of the water and place it on a cloth to cool down. Completely clear means completely clear - If there is even one crystal continue to boil until it melts. Hold the pad up against a light and make sure there are no crystals left.5. When the pad cools down it is ready to be used again.6. If crystals start forming while the pad is cooling repeat steps 1 2 and 3.