Non-contact thermometers use infrared technology. What that means is they have a sensor which collects infrared rays that are emitted by the patient. All living beings produce infrared energy and the forehead has a very rich vascular supply which has been recognised as a very good site to measure temperature for thousands of years. TRITEMP™ uses multiple algorithms to convert the temperature from the forehead to a core body temperature which is then used to diagnose the patient along with the other vital signs.