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Temperature checks and ‘deep cleaning’ aren’t good at stopping coronavirus. So why do we bother?

Temperature checks, although widely used, aren't a very effective screening tool for COVID-19, experts say.
Temperature checks, although widely used, aren't a very effective screening tool for COVID-19, experts say. Getty

If you’re heading to a gym lately, you might be asked to wash your hands, have an infrared gun pointed at your head and wait for an army of workers to sanitize every surface before you touch a machine — all in the name of safety.

But how much of a difference do these kinds of measures make when it comes to coronavirus transmission?

The evidence is mixed, some experts say. And measures might not always be there for the reasons you think.

CDC updates official coronavirus symptom list
CDC updates official coronavirus symptom list

Take temperature checks, which are currently being performed at several Canadian airports. Some businesses, like the Apple Store, have also been checking customers before they enter.

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“We know that this is not effective,” said Colin Furness, an infectious disease epidemiologist with the University of Toronto.

“I mean, really, just as a screening tool it’s not effective at all.”

Given that people can spread the virus before ever showing symptoms, he said, checking someone’s temperature is definitely not a guarantee that they’re healthy. Illnesses other than COVID-19 can raise a person’s temperature, too.

“And if you really want to get on that plane, you take a Tylenol and you’ll glide right past that temperature check,” Furness said.

Read more: Can I refuse a temperature check? What to know about the COVID-19 screening tool

Even the U.S. Food and Drug Administration notes that non-contact thermometers aren’t a very good screening tool.

“Even when the devices are used properly, temperature assessment may have limited impact on reducing the spread of COVID-19 infections,” the agency wrote on their website.

“Some studies suggest that temperature measurements alone may miss more than half of infected people.”

A recent commentary published in the journal Travel Medicine and Infectious Disease also said that temperature checks on young adults were “virtually useless” for screening.

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Coronavirus outbreak: Temperature checks remain part of COVID-19 detection though not all cases present with fever
Coronavirus outbreak: Temperature checks remain part of COVID-19 detection though not all cases present with fever

Furness thinks that plastic gloves are also an especially useless way to prevent coronavirus transmission. Hospital workers wear gloves when dealing with things that might be absorbed through the skin, he said, but this isn’t a concern with COVID-19.

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“You can’t clean your hands when you’re wearing gloves. So as a matter of fact, if anything, you’re making the situation potentially worse.”

Read more: The coronavirus doesn’t spread easily through contaminated surfaces, CDC clarifies

The surfaces themselves are also less of a concern than perhaps we once thought, said Dr. Stan Houston, a professor in infectious diseases at the University of Alberta.

“I think people are feeling that the evidence is going away from that as being a major risk. And of course handwashing will mitigate that,” he said.

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“I think a big effort at scrubbing everything down is probably an inappropriate focus.”

The CDC, on its website, notes that while it may be possible to catch the virus by touching a contaminated surface and then your nose or mouth, “This is not thought to be the main way the virus spreads.”

“There’s an obsession there that we have around touch, and it’s out of proportion to where the COVID risk is,” Furness said.

“So people will be very abstemious about touching, but then they’ll go and hang out in a bar or a restaurant where people aren’t wearing masks. And that’s dangerous.”

Read more: Masks more important than disinfectant for COVID-19 prevention, experts say

While public health experts contacted for this story all believe that masks are an extremely effective means for reducing transmission of the coronavirus indoors, Houston said that it’s not generally necessary to wear them outdoors.

“Any virus is just being massively diluted by the infinite space of outdoor air and being dispersed by air currents.”

Furness agrees, saying that unless you’re in a dense crowd, there is no need to wear a mask.

The psychology of ‘deep cleans’

So if these methods aren’t very effective at keeping coronavirus away, why do we bother?

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Partly, said Stephen Hoption Cann, an epidemiologist and clinical professor at the University of British Columbia’s School of Population and Public Health, it’s because our knowledge of the virus is changing all the time.

“We just sort of try and follow the latest information coming out. And so, some things that were recommended in the past may change over time,” he said.

Public health authorities were conservative in their advice at first, he said, and now we have a better understanding of how the virus spreads — mostly through droplets or the air — but we keep to our old habits.

Why do some people strongly oppose pandemic health guidelines?
Why do some people strongly oppose pandemic health guidelines?

Another reason, according to Steven Taylor, a professor and clinical psychologist at UBC who studies the psychology of pandemics, is that cleaning and other such measures help fulfill a biological need.

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“A biological immune system is not enough to keep us safe from pathogens,” he said. So, people have developed reactions to try to keep themselves from getting sick, which he calls a “behavioural immune system.”

“We’re hardwired to avoid dirty surfaces as sources of contamination,” he said. We’re also hardwired to want to interact with people — so we clean obsessively, rather than social distancing, which would be more effective at stopping this particular virus.

Read more: Our mental health won’t be the same after coronavirus pandemic, experts say

People also feel a need to “do something” to protect themselves, he said, and this extends to governments and other institutions, who want to be “seen as doing something.”

“Cleaning is an obvious, dramatic, demonstrable thing. You’re actually doing something, whereas wearing a mask is not doing a whole lot. You’re not making special efforts.”

For this reason, he said, he sees some psychological value in things like temperature checks and disinfecting credit card machines at a store. “That’s not going to have much of an impact on the spread of infection, but it can make people feel calmer.”

Covid-19 coronavirus: the psychology of pandemics
Covid-19 coronavirus: the psychology of pandemics

These things can also provide cues, he said, that remind people to continue to take actions that make more of a difference — like social distancing and wearing masks.

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Keeping to a limited social circle helps too, Hoption Cann said.

So does minimizing time spent indoors, unmasked, with a group, he said. “Here in B.C., Dr. Bonnie Henry mentioned that a lot of the recent cases they’re seeing are private parties. So these are people indoors, in contact with each other for a prolonged period of time, which allows the virus to spread from one person to another.

“So in that setting, wiping down surfaces, it’s not really going to help. Or even staying two metres apart if you’re in prolonged contact with just one person who may be infectious at the party.

“It’s much better to just avoid those situations altogether.”