Finding and isolating coronavirus cases is key for curbing virus spread until there is an effective vaccine. Officials say temperature screenings upon entry to businesses and other places can be useful, but they advise pairing the technique with other screening measures too.
The Food and Drug Administration (FDA), for example, has warned that even when temperature assessment devices are used properly, they may have a "limited impact" on reducing the spread of infections. It has been estimated that up to 40% of infected individuals are asymptomatic and could potentially breeze past this screening method undetected with the opportunity to further spread the virus.
“Screening employees is an optional strategy that employers may use,” according to guidance from the Centers for Disease Control and Prevention (CDC). “Performing screening or health checks will not be completely effective because asymptomatic individuals or individuals with mild non-specific symptoms may not realize they are infected and may pass through screening."
In addition to temperature screenings, the CDC says to focus on screening questions for “new” or “unexpected” symptoms, including fever or feeling feverish (chills, sweating), new cough, difficulty breathing, sore throat, muscle aches or body aches, vomiting or diarrhea and new loss of taste or smell.
“During outbreaks, one can argue that it's likely most of the fevers will be secondary to the outbreak, and hence it will help in detecting symptomatic coronavirus cases,” Dr. Waleed Javaid, director of Infection Prevention and Control at New York's Mount Sinai Downtown, wrote in an email statement to Fox News.
He said the effectiveness of temperature screenings depends on the tool, sensitivity, operator, operator training and margin of error, among other factors.
“If any such tool is being used, it should be tested, instructions of use followed and understanding of the margin of error (how many degrees), etc.,” Javaid said.
For employers conducting temperature assessments, the CDC says to stand behind a physical barrier, such as a glass or plastic window or partition to protect the screener’s face from potential exposure to infected respiratory droplets.
The employers should make a visual inspection of the employee for signs of illness, like flushed cheeks, fatigue, coughing or shortness of breath. Also, officials say to always wear a clean pair of gloves for each employee and thoroughly clean thermometers between each check.
The CDC considers a person to have a fever at 100.4°F or greater or when they feel warm to the touch or give a history of feeling feverish. However, the CDC says a lower temperature threshold — 100°F, for instance — can be used, particularly in health care settings.