Do infrared thermometers emit radiation and damage the pineal gland? No, that's not true: Such thermometers are passive; they don't emit infrared radiation. They simply detect infrared energy. Furthermore, the pineal gland is not near the forehead; it's close to the center of the brain. A leading expert in the field dismissed the idea that it could be harmed by the use of such thermometers as "outrageous."
The claims were made in a video (archived here) published by YouTube on August 11, 2020. The post was titled "Aiming A Temperature Gun At Your Head" and included the following text:
Dear all. Please do NOT let anyone point a temperature gun at either your or your children's forehead!!!! Please listen and share.
Click below to watch the video on YouTube:
The video shows a man reading a purported post from an anonymous Australian nurse. The nurse talks about using an infrared thermometer, pointed at the forehead, to measure a person's temperature. That post says, in part:
As a medical professional, I refuse to directly target the pineal gland which is located directly in the center of the forehead, with an infrared ray. However, most people agree to go through this several times a day! Our pineal glands must be protected as it is crucial for our health both now and in the future.
The post is wrong for at least two reasons. One, non-contact infrared thermometers do not emit an infrared ray or radiation. The thermometers simply measure the infrared energy radiated from the body. See here for one company's explanation for how its forehead thermometer works. See here for another.
Jim Seffrin, director of the Infraspection Institute in New Jersey who recently wrote a training course on how to use infrared instrumentation to accurately measure body temperature, summed it up:
Infrared thermometers, also known as non-contact thermometers, are completely passive. They do not emit anything ... These devices sense the normally-invisible infrared energy -- you can think of that as heat, given off by any object here on earth, humans included -- and convert that heat energy into a temperature value.
Infrared devices are not lasers, although some models of thermometers have lasers for aiming. If you have such a device, Seffrin recommends that you turn off the laser. When you're a few inches from a person's forehead, you don't need help with aiming and lasers should be kept away from a person's eyes. Still, such lasers would not be penetrating. Again, here's Seffrin:
They're not going to reach through flesh, muscle, bone, brain tissue to reach the pineal gland, which is at the center of the skull. That's absolutely outrageous.
His comments point to the second reason the post is wrong. Namely, it states that the pineal gland is located "directly in the center of the forehead." It's not. It's much deeper, located between the brain's two hemispheres.
Elsewhere in the video, the anonymous Australian nurse is quoted as saying:
I started taking the temperature on the wrist, which turned out to be more accurate given that the forehead is cooler than the wrist and the results differ by more than one degree in some cases.
However, medical experts generally agree that the mouth, rectum, forehead, ears and armpits are the best places to check for a fever. Of those, rectal temperatures are the most accurate, although not very convenient to obtain. By contrast, one of the biggest benefits of non-contact infrared thermometers is that they are relatively quick and easy to use. The U.S. Food and Drug Administration outlines the various benefits, limitations and proper use of such thermometers. Note that there is no mention of radiation, the pineal gland or any related risks associated with using non-contact infrared thermometers.