The Therapure��� Ultrasonic Humidifier fills your home with healthy moisturized air. It even helps to reduce flu viruses in homes as scientific research has shown that humidity levels between 40-60% can reduce flu virus in the air and on surfaces. Cool Mist helps you breathe and sleep more comfortably by reducing dry nose and itchy cracked skin Warm Mist helps relieve your cold and flu symptoms by relieving congestion coughs and soothes a sore throat.