A temporal artery thermometer (TAT) is a non-invasive device used to quickly measure a person’s body temperature in clinical environments and home settings. This handheld instrument scans the forehead area to capture heat radiating from the underlying superficial temporal artery. TATs are valued for their ease of use and ability to provide a temperature reading without causing discomfort, making them ideal for children or sleeping patients.
How Temporal Artery Thermometers Work
Temporal artery thermometers use an infrared sensor to detect heat emitted from the skin’s surface. The target is the superficial temporal artery, a branch of the carotid artery that runs just below the skin on the forehead and temple area. Because this artery is close to the surface and continuously fed by blood from the body’s core, it serves as a reliable proxy for core body temperature.
The sensor takes multiple readings as it moves across the skin. The device uses an internal algorithm, often called the Arterial Heat Balance (AHB) system, to convert the measured skin temperature into an adjusted core body temperature reading. This algorithm accounts for ambient temperature and skin cooling, ensuring the thermometer captures the highest temperature point over the artery.
Step-by-Step Guide to Accurate Use
Achieving an accurate reading requires proper preparation of the site and the device. Before use, the sensor lens must be clean, and the patient’s forehead must be free of obstructions like hair, hats, or heavy makeup. If the forehead is sweaty, dry the area or wait a few minutes, as evaporative cooling can lead to a falsely low reading.
To take the temperature, press the scan button and keep it depressed throughout the entire process. Place the probe flush against the center of the forehead, and gently move the device in a straight line across the forehead toward the hairline near the temple. Maintain continuous contact with the skin and avoid curving the path down the side of the face, which could miss the artery.
For some models, if the forehead is moist, the scan should be extended to touch the soft depression on the neck just behind the earlobe. This secondary measurement helps the device compensate for evaporative cooling. Release the button only after the scan is complete, and the final temperature reading will be displayed.
Why Choose a Temporal Artery Thermometer
A primary advantage of the temporal artery thermometer is its speed, often delivering a result in just a few seconds. The non-invasive nature increases patient comfort, allowing for temperature checks on infants, children, or sleeping individuals without disruption. This ease of use and lack of contact with bodily fluids makes it a hygienic choice for home and clinical environments.
However, temporal artery thermometers do have limitations. Readings can be impacted by external factors such as direct sunlight, cold ambient temperatures, or a sweaty forehead, which can affect the skin’s surface temperature. They are also more expensive than basic digital thermometers. While accurate for screening, if a precise core temperature is needed, a physician may recommend a more invasive method.