Forehead Temperature Scanners for COVID-19: Are They Effective?

One thing about COVID-19 that's universally apparent: It's scary. We'd do anything to protect ourselves from it, from denialism (not good) to social distancing for a year. If we could shop our way out of the pandemic, we'd absolutely try it — but before we spend that money, it's good to know what the science says.

One product that's become more ubiquitous recently is the forehead temperature scanner. Businesses, medical practices, and other organizations have begun requiring that you submit to a temperature check before entering their premises. An elevated body temperature can indicate fever, which can indicate the presence of COVID (or, at the least, an unpleasant cold).

Physiologists at England's University of Portsmouth aren't so sure the forehead zap is such a reliable measure of illness, though. In new research, the scientists laid out four reasons why these handheld devices might provide a false sense of security. First, those who have COVID and are shedding the virus may not have a fever until they've already become infectious. Next, fever may exist deep in the body, but not at the surface. Third, a high temperature might not indicate COVID — even things like hearing aids can alter that measurement.

Finally, you're more likely to get an accurate reading of body temperature in the first place by taking readings from two points: the eye and the finger. This isn't to say that taking temperature or even knowing your own baseline temperature is a waste of time, but if you're shopping for forehead scanners, you might want to redirect your money elsewhere.