Digital temperature checks just one step in preventing COVID spread

Temperature checks are required before entering school, work, even the gym – but how accurate are digital forehead thermometer readings?

"I usually get the same temperature, and everyone around me usually gets like about the same thing," said Carmen Pyrtle.

Local teacher Carolina Trainer said “the numbers are all over the place.” She added that some days she thinks the temperature checks are a waste of time.

Parents said they’re also frustrated with accuracy. Jen Barr said her Wake County elementary school students were sent home because the school readings were higher than when she checked at home.

5 On Your Side spoke with Dr. Anita Skariah about the discrepancies.

"When you’re using these thermometers, it’s measuring the surface temperature of your skin. It’s not necessarily the internal temperature," said Skariah. "So there is some variability in how accurate it is from that standpoint."

"They can vary by a half to one degree Fahrenheit," she added, explaining that variables including a sweaty forehead, blowing car heat in line at carpool, distance from the thermometer and even the angle of the thermometer can impact results.

For the most accurate results Skariah recommended being perpendicular to the device.

If you’re at an angle and doing it you’re not going to get an accurate reading, it’s got to be directly or full-on,” she said.

In Wake County, a student with a temperature of 100.4 degrees or higher is rechecked after five minutes. With a second high reading, they’re sent home.

A school spokeswoman said some students with high readings later tested positive for COVID-19, which is one reason many health experts agree that temperature checks are one possible detection tool to help slow the spread.

"Fever is only one aspect of the symptoms, and not many people have fever, necessarily, who have COVID," said Skariah. "They’re just trying to mass screen folks and try to narrow it down, and then we have to narrow it down further."

Mass screenings at Wake County schools include questions about symptoms and possible exposure before students are allowed in.

If you get a low reading on your thermometer, it’s not because the battery is low. It can happen if you’re not close enough to the thermometer or if you’ve been out in the cold for a while, so give yourself a moment to warm up.

As for which type of thermometer to use, many doctors rely on under-tongue digital thermometers for the best accuracy, but given the pandemic, non-contact thermometers are also useful.