The Infrared Thermometer accurately measures a person body temperature in as little as one second. A reading is taken as soon as an individual forehead is detected within 2-4 inches of the thermometer¡¯s sensor. A green light will indicate that their temperature is within a normal range, and a flashing red light and audible alarm will indicate that the person has a high temperature. The Infrared Thermometer can be used to quickly test large volumes of people without causing delays.