Infrared thermometers might be 'hygiene theatre,' but they won't harm your brain
TORONTO -- The infrared thermometers increasingly being used as COVID-19 screening measures at Canadian entry points and businesses are not able to catch every case of the novel coronavirus, but there is no reason to believe they will harm your brain.
That latter claim has been circulating on social media in recent weeks, including in a video that has garnered more than two million views since it was posted to YouTube on Aug. 11.
In the video, a man shares a social media postof which he says he does not know the origin, attributed to "an Australian nurse" for whom no name is given.
The author of the post says that "an infrared thermometer must never be pointed at someone's forehead, especially babies and young children," but does not provide any evidence to back that up. He or she seems especially concerned with the pineal gland, a small organ that produces melatonin and other hormones, but does not explain why that the gland is in any way affected by the use of forehead-scanning thermometers.
That, experts say, is because there is no evidence.
"There's zero truth to that claim," Dr. Isaac Bogoch, an infectious disease specialist with Toronto's University Health Network, told CTVNews.ca on Thursday via telephone.
"I honestly don't know what to say about it. It's insane, it's wrong, and it's crazy that something like this could still be amplified and even believed."
Moreover, while the post quoted in the video expressed concern about "infrared rays" coming from thermometers, infrared thermometers do not transmit any rays or any other form of radiation; they only measure infrared wavelengths coming from the body.
"It's not sending any kind of signal," Dr. Haris Sair, director of neuroradiology at Johns Hopkins University, told The Associated Press in July.
Additionally, Sair said, the thermometers measure temperature at the body's surface – not several centimetres into the brain, where the pineal gland is located.
The Australian Associated Press reported Aug. 25 that similar claims had been made in widely-circulated posts on Facebook and Instagram. The Instagram post it referenced has since been flagged by the platform as containing verifiably false information.
Infrared thermometers are considered to be more expensive and less accurate than those that measure body temperature by being inserted into the mouth. However, many businesses have chosen to use them because the lack of direct contact means they do not need to be sanitized every time they are used on a new person. Temperature checks with these thermometers have been mandatory at Canadian airports since June.
Temperature checks do not catch all COVID-19 patients, though, missing those who are asymptomatic as well as symptomatic patients who do not count fever among their symptoms.
This has led to criticism of the use of forehead temperature checks at entry points as a form of "hygiene theatre" – more about creating the perception of safety than ensuring that the virus is actually kept out.
"In general, they're just not that effective," Bogoch said.
"There's a lot of reasons well beyond COVID-19 for people to have fevers, so you might get some false positives – and of course you're going to miss a lot of people that just don't have a fever at the right place at the right time."
Dr. Anthony Fauci, director of the U.S. National Institute of Allergy and Infectious Diseases, said last month that the White House had stopped using the "notoriously inaccurate" temperature checks at its entrances.
Even though infrared thermometers are not very effective when it comes to stopping the spread of COVID-19, the psychological benefit their presence provides is real – and for that reason, Bogoch said, there might still be value in keeping them in use.
"I'm not discounting these devices altogether, because I think the psychology is important," he said.
"It looks like they're taking this seriously and they've got safety protocols in place – whether or not the safety protocol is effective is another story – but the optics are important to many."
With files from The Associated Press