Ultrasonic humidifiers are the popular humidifiers. Ultrasonic humidifiers are really safe and hence they are mostly used in kid’s rooms and nurseries. Like other humidifiers ultrasonic humidifier will also maintain the humidity level and thus will prevent us from getting cold, cough, nosebleed and other respiratory troubles. In ultrasonic humidifiers high frequency sound waves are used to create the mist in the air. That is why the air remains cool. In other humidifiers the surrounding air becomes hot which can cause steam burns.