Moisten cotton liner with bottled, filtered, or distilled water, and place over the back of D.E.R.M.Â® mask. Place D.E.R.M.Â® with liner on a paper towel and microwave on high for 20 seconds (1000 Watt Microwave). Test temperature with your fingers. If it feels hot to the touch, wait one minute and test again. When the temperature feels comfortable, gently place the mask and liner over closed eyes. Wear for 7-9 minutes or as directed by your eye doctor.