HealthyLine Mask can be used hot or cold. The heat helps to reduce nasal congestion and relieves soreness and swelling. Cold relieves dry, puffy eyes as well as sinus headaches. It also helps remove the sting from a brow wax and reduces inflammation after a cosmetic procedure.Hot: Place in microwave on medium for 35 - 45 seconds.Cold: Place in freezer for 30 minutes.Chill it in the freezer or fridge or pop it into the microwave. Place it over your eyes and sinuses, or slide it to your forehead. Contains one eye mask EXPERTLY DESIGNED TO RELIEVE: Puffy Eyes Headaches Sinus Problems Allergies And More!