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May 18, 2020

Is 99.5 degrees a 'fever'? It's a surprisingly tricky question—with big implications for coronavirus response.

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    As states begin to reopen nonessential businesses amid America's new coronavirus epidemic, the lack of a national strategy for screening workers for Covid-19 has resulted in body temperature thresholds that vary by state, the Washington Post's Todd Frankel reports.

    Your top resources for Covid-19 response and resilience

    Reopening plans show states and employers have different definitions of a fever

    In states that are moving to reopen nonessential businesses, officials are developing Covid-19 screening guidelines to help industries determine which workers are well enough to come to work—as well as which workers might be showing signs of Covid-19, the disease caused by the new coronavirus.

    But there currently is no national Covid-19 screening strategy for workers, Frankel reports. As such, states have been establishing their own screening guidelines, leading to differences in the set body temperature thresholds that workers must meet to be allowed to return to work.

    For instance, Connecticut, Georgia, Ohio, and Pennsylvania in their screening guidelines say employees can return to work if they have a temperature of 100.4 degrees or lower. In Texas, the cutoff is 100 degrees, and in Delaware, the cutoff is 99.5 degrees. Other states, such as Maryland, have yet to release any guidelines for fever screenings, Frankel reports.

    Temperature guidelines also vary between companies, according to Frankel. At Amazon, for instance, workers with a temperature of 100.4 degrees or higher are not permitted at work. In comparison, Walmart does not allow employers to be at work if they have a temperature of 100 degrees or higher.

    Other aspects of the guidelines have been a source of confusion for employers, as well. For example, some states, such as Connecticut, recommend that employees take their own temperatures at home, while Texas suggests that businesses screen employees for fever, Frankel writes.

    Daniel Kaplan, an attorney with Foley & Lardner, said the inconsistencies have led companies to seek help in understanding the guidelines. "We're seeing differences among the states that aren't necessarily explicable," Kaplan said.

    Should there be a national screening strategy?

    According to David Thomas, director of the Division of Infectious Diseases at Johns Hopkins University School of Medicine, one reason the screening guidelines are so inconsistent is that "[t]here's no binary absolute value for a fever."

    Most laypeople define a fever as having a body temperature above 100 degrees, Frankel reports. However, Frankel notes that most doctors consider a person to have a fever if their body temperature is 100.4 degrees or higher.

    Even CDC fails to provide a clear definition for a fever, Frankel reports.

    CDC's Covid-19 screening guidelines for employers recommend that companies screen workers to ensure they don't "'have a temperature or symptoms'" of Covid-19, but the guidelines "don't define what that temperature is," Frankel writes.

    Frankel notes that although fevers are never a perfect method of detecting illness, body temperature "is the one symptom that can be measured and checked externally—an especially important distinction given the scarcity of rapid [Covid-19] diagnostic testing."

    As such, some public health experts are calling for a national screening strategy for workers.

    Without one, Steven Lawrence, an infectious-disease specialist and professor at Washington University in St. Louis, asked, "Where do you set the bar?" and "[W]hat is your threshold for risk?" He said, "I think it would make it easier if there was one standard temperature we were using" (Frankel, Washington Post, 5/15).

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