After placing the hot pack unit inside the cover, plug the unit in and lay it out flat on a glass or Formica table or counter top. Either hold the switch down (if you are using the Thermophore Classic™) or push the "on" button (if you are using the MaxHEAT™ style). Let the unit warm for about 5 minutes to activate the moisture in the fleece cover. When you pick up the pad at the end of 5 minutes, you should see tiny moisture drops on the glass or Formica surface. If you run your hand over the surface, you can feel the moisture and see streaks of water.
If you live in an area with a dry climate, or frequent use of the furnace or air conditioner makes the indoor air too dry, you may need to use our Moisture-Plus™ cover. It will utilize atmospheric moisture, but also has a separate vinyl pocket that allows you to add a damp cloth for added moisture.