1. Bend the metal foil inside the pad once or twice so that the liquid inside crystallises.
2. When crystallisation is complete, it is ready for use. The pad will reach a temperature of 40 to 43°C, cooling progressively over an hour, depending on the ambient temperature. By kneading the pad from time to time the heat can be maintained for approximately 1/2 hour more.
3. Before reusing the pad, place it in boiling water for about 5 minutes until the crystals have completely changed to liquid form.