USF professor explains why thermal scanners may not work well for body temperatures

Posted at 12:53 PM, Jun 23, 2020
and last updated 2020-06-23 14:38:03-04

TAMPA, Fla. — As business are starting to reopen due to COVID-19, we're hearing more of them are using thermal scanners to test body temperature.

Many national reports have indicated those scanners aren't reliable when it comes to looking at body temperatures.

We reached out to USF professor Frank Pyrtle, III. He teaches mechnical engineering at USF and has used thermal scanners in some of his research.

"There is a lot of error associated with those kinds of devices," explains Pyrtle, especially when used in environments that aren't controlled.

"Using a thermal scanner to scan someone's face is not going to be that accurate. You can certainly pick out the people that have a higher temperature but you just don't know why," explains Pyrtle.

Pyrtle tells us that being a hot car before entering a cold building can certainly play a role, even make-up on a woman's face could alter the temperature reading from a thermal scanner, even a type of medicine could have an impact on the temperature reading.

"On the image, it may look as though the temperature on their face is high, oh we think they may have a cold or may be sick, but it's not actually that," says Pyrtle.

The thermal scanners are something you've probably seen in movies or tv shows, oftentimes used by police departments in a helicopter to catch criminals.

They use infrared technology to determine a temperature or energy coming off a surface.

"In a research environment I would have to be concerned other sources of that energy reflecting off of the surface," says Pyrtle.

Another issue, Pyrtle says is the margin of error in thermal scanners. They're better at determining the temperature differential.

"If 98 is normal, 100 means your sick. That's a 2-degree temperature difference and most thermal scanners or cameras that is well within their error," says Pyrtle.