When Gauging COVID, Body Temperature Is Ineffective

When it comes to effective gauges of COVID, body temperature, and related screening and testing, is not foolproof. 

In the latest news, body temperature has been confirmed to be an ineffective gauge of COVID infections, with substantial evidence of varying body temperatures, inaccurate readings, problematic definitions of fever presented, and asymptotic individuals validating the data. 

Lack Of Credible Definition Of Fever

An increased deep body temperature is indicative of fever. And until now, fever has been considered one of the leading signs of COVID. However, as medical science has now proven, increased body temperature may be a result of other factors unrelated to COVID which include hormonal activity, environment, and weather, as well as physical activity. 

As a medical publication interestingly points out, fever is the most commonly reported manifestation of COVID. In this context, the meaning of “fever” varies depending on the cutoff temperature used, the type of thermometer, the time of the day, the site of measurements, and the person’s gender and race. 

The absence of a universally accepted definition, and meaning, for fever has been especially problematic during the current COVID-19 pandemic. Now, it’s proving even more problematic.

With this lack of precision in defining fever and confirming its connection to COVID infection, it is difficult to render a single, universally accepted temperature cut-off that accurately defines a COVID-associated fever. With this, what is meant by ‘fever’ is uncertain.

Generalizable Set Of Characteristic Signs And Symptoms

CDC, too, limits the definition of a generalizable set of characteristic signs and COVID symptoms. ‘Generalizable’ is the word of focus here. At best, current evidence and studies suggest substantial variability ranging from mild to severe and this variability is based on only partially described patient-level factors. Variability is another word of focus here. 

While published summaries of COVID symptom descriptions and observed frequency exist, basing this on generalizability and variability pulls one of the symptoms, fever, into question. 

While 83% – 99% of individuals develop a fever, this is a generalization with no scientific data or evidence proving that fever is, without a doubt, a COVID symptom. With this data, body temperature is not an effective gauge of COVID.

Limitations Of Temperature Screening Devices

Since the start of the COVID pandemic, temperature screening for fever at airports, workplaces, schools, and shopping malls has been conducted.  

A recent journal adds to this by stating that based on symptoms associated with COVID, which include fever, the most common preventive procedure consists in measuring body temperature before entering shops, public offices, or workplaces and hospitals.

However, for some time, the role of this screening has been questioned. Recent perspectives now believe that screening of this kind with thermal scanners is ineffective in identifying fevers and with this, controlling the spread of COVID.

While temperature screening has been a focal point of COVID case detection, limitations of body temperature checking, procedures, and devices, the focus has now shifted to the inability of the latter to recognize fever.

Limitations Due To Asymptomatic Individuals

One of the other limitations of recognizing fever and associated COVID infection is that some infected individuals are asymptomatic. Being asymptomatic, these individuals would not possess raised body temperatures or show signs of fever. Having no fever would single a negative test result when in fact the individual is infected.

Adding to this, according to a recent study, fever was uncommon among hospital patients who tested positive for COVID. Even when attempting to account for variability in temperature by considering repeat testing, sensitivity did not improve to useful levels.

Furthermore, the fever had a low sensitivity for COVID bringing up questions regarding any utility of widespread temperature screening. The sensitivity of fever appeared even lower in the initial stages of the illness when compared to mid-illness. As a gauge of COVID, temperature testing would thus be ineffective depending on the stage of infection within the individual.

With this, as the Journal points out, using fever as a screening tool for COVID provides a false sense of security. While screening for fever may have alternative public health benefits, its value in excluding COVID is limited and ineffective, if not impossible.

Make Use Of Other Effective Gauges And Safety Precautions

In a time of great concern, it is important to remain cautious, practice health and safety measures as defined by the Centers for Disease Prevention and Control and keep an eye on daily physical health changes. 

As measures are concerned, generic public health tactics such as self-isolation when ill or experiencing a high temperature, as well as physical distancing and contact tracing, are considered more effective than widespread temperature screening.

When it comes to body temperature as a gauge for COVID, rather consult your doctor should your temperature be raised to fever levels of more than 100.4 degrees. 
High temperatures should always see individuals err on the side of caution. Especially when high temperature is picked up when using the right temperature device, testing at the right time of the day, and following proper testing procedures which include the correct anatomical site at which temperatures are taken. If in doubt, consulting a health professional and conducting an FDA-approved COVID test is advised.