How much do touchless thermometers protect you from COVID-19?

CARY, N.C. -- Many businesseses are investing in touchless thermometers to keep patrons safe from COVID-19.

In March, health officials touted fever as one of the most common symptoms of COVID-19. Now, six months later, new research shows fever isn't the predominant symptom.

The Centers for Disease Control and Prevention reported 44% of hospitalized patients had a fever, but fatigue, headache and muscle aches were more common in people who were not hospitalized.

Multiple other studies found a large percent of patients who tested positive for COVID-19 showed no symptoms.

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Despite this research, doctors' offices, schools and restaurants are still implementing touchless thermometers into their screening processes. The thermometers are quick, easy to use but the U.S. Food and Drug Administration warns, "be aware that, even when the devices are used properly, temperature assessment may have limited impact on reducing the spread of COVID-19 infections."

Schquthia Peacock, a family nurse practitioner in North Carolina, said while medical understanding of COVID-19 symptoms has expanded and changed, she still finds the touchless thermometers useful.

"I think there is a purpose because often times people don't realize their temperature is increased, you know?" Peacock said. "It's erring on the side of extra caution which I think is absolutely necessary."

We brought Peacock three different touchless devices to compare how they worked against each other and an oral thermometer. Each of the three devices, purchased online, had thousands of reviews. The team used the following brands: iHealth, Berrcom and Femometer.

An average temperature for a healthy adult is 98.6F (37C) and the Centers for Disease Control and Prevention considers 100.4F (38C) a fever.

When tested on a person, the forehead thermometers read a temperature between 97.4F - 98.2F. The oral thermometer Peacock uses in her practice read the same individual's temperature as 98.5F.

Peacock said it's normal for temperature to vary between an oral and forehead reading. She said forehead devices tend to read .5 to 1 degree Fahrenheit lower than an oral device. All of the devices sampled fell into this error range.

"Oral is going to give you the most accurate temperature compared to forehead or infrared thermometers," Peacock said. "The infrared thermometers are going to be reading what's on your forehead so it's less accurate that oral because it's closer to what's considered your core."

Peacock also noted that weather and time spent in the sun can cause a reading from a forehead thermometer to be higher.

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She said thermometers should not usually read lower than 97F, and if they do, businesses and individuals should use caution when relying on the device.

"I think when people are using it as an evaluation tool they should make sure they are using a reliable tool," Peacock said. "I think this report probably proves that these three probably give you an idea of reliability, to make sure that they're reading the reviews and--now that thermometers are more available--maybe reassess what thermometer they're using and maybe make a better purchase if necessary."

She cautions people to take note of their devices consistently returning lower results. Also, note if batteries are old as it could impact results as well.

"Use these as a screener tool and one-piece, one variable, in that screening process and understanding that that screening, you would have less concern if you followed those three W's we hear so much about," Peacock said.