Physicians say non-contact infrared thermometers fall short as COVID-19 screeners

And some people are like me.  I almost never get a fever when I'm sick.

 

https://www.eurekalert.org/pub_releases/2020-12/jhm-psn121520.php

 

News Release 15-Dec-2020
Johns Hopkins Medicine

 

While a fever is one of the most common symptoms for people who get sick with COVID-19, taking one's temperature is a poor means of screening who is infected with the SARS-CoV-2 virus that causes the disease, and more importantly, who might be contagious. That's the conclusion of a perspective editorial by researchers at Johns Hopkins Medicine and the University of Maryland School of Medicine that describes why temperature screening -- primarily done with a non-contact infrared thermometer (NCIT) -- doesn't work as an effective strategy for stemming the spread of COVID-19.

•••••

"Readings obtained with NCITs are influenced by numerous human, environmental and equipment variables, all of which can affect their accuracy, reproducibility and relationship with the measure closest to what could be called the 'body temperature' -- the core temperature, or the temperature of blood in the pulmonary vein," says Wright. "However, the only way to reliably take the core temperature requires catherization of the pulmonary artery, which is neither safe nor practical as a screening test."

•••••

Another problem with NCITs, Wright says, is that they may give misleading readings throughout the course of a fever that make it difficult to determine when someone is actually feverish or not.

"During the period when a fever is rising, a rise in core temperature occurs that causes blood vessels near the skin's surface to constrict and reduce the amount of heat they release," Wright explains. "And during a fever drop, the opposite happens. So, basing a fever detection on NCIT measurements that measure heat radiating from the forehead may be totally off the mark."

•••••