Perfecxa Non contact Infrared thermometer is unique and handy in design with fast measurement. It can be switchable from Centigrade to Farehnite and vice versa. It has 3 backlit display colours. It changes according to tempearature readings. The temporal artery is connected to the heart via the carotid artery. So it is designed to measure the skin surface around temporal artery, a major artery of the head .Aim the thermometer at the center of the forehead with a distance of 2 to 3 cm and then press the SCAN BUTTON. Note: Do not remove the thermometer from the forehead before hearing the final beep.