Remove the silicone cap and carefully fill your massager with hot water, then carefully replace the cap and enjoy! The higher the water temperature, the longer your massager will retain heat. You should use warm/hot but not boiling water and always test on your hand before you apply to your face. You may also use the Lanshin Massager by ACERA without water for a more neutral feel. CAUTION. Please carefully test the temperature on your hand or arm prior to each use to ensure a comfortable temperature (especially before using it on face or on others). If you find it too hot, let it cool until it reaches a more comfortable temperature. Note: After adding water and replacing the cap, a few drops of water may escape from the top. This is not a defect in the tool and will not affect performance. Simply wipe-away the water and continue use. (Using slightly less water and filling 3/4 full may resolve this.) Care: To clean, simply remove the silicone shell and wash everything with soap and warm water. Please note, the Lanshin Massager by ACERA is NOT microwave or dishwasher safe.