Ask A Doctor: How Temperature-Taking Helps Slow COVID-19 Spread, And What To Do If You Have Symptoms

A UT Health San Antonio physician answers listeners’ questions about their health during the coronavirus pandemic.

By Michael MarksMay 14, 2020 7:57 am,

In this week’s installment of Ask a Doctor, UT Health San Antonio physician Fred Campbell answers Texas Standard listeners’ most pressing questions about the coronavirus.

Why is temperature-taking done so often when it can’t identify asymptomatic carriers or someone in the early stages of a COVID-19 infection? 

Public health workers often take a person’s temperature when interacting with them in a high-risk situation. In those cases, having a fever makes an individual statistically more likely to be infected with COVID-19. 

“Quite often we take temperatures in situations that are very high risk where individuals could rapidly spread the infection,” he said. 

But having a normal temperature doesn’t indicate, definitively, that an individual is free of the coronavirus.

Should business owners always take patrons’ temperatures, and should people avoid businesses where temperatures are not taken? 

Campbell said he would insist that business owners take customers’ temperatures before entering an establishment because it reduces the statistical likelihood that an infected person would pass the virus to someone else.

How can someone protect themselves if someone in their household isn’t practicing social distancing and insists it’s safe to go out without a mask?  

Campbell said living with a person who engages in “reckless” behavior with regard to the virus puts everyone in the residence, including those most vulnerable to infection, at risk. 

“Virtually everyone will develop the infection if they’re exposed long enough,” Campbell said. 

If a person has mostly complied with stay-at-home orders, worn a mask when going to the grocery store and otherwise followed health guidelines, what’s the appropriate response to feeling a little under the weather? Should they ride it out or seek medical attention? 

Many cases of COVID-19 are not fatal, or even serious. But it’s difficult to predict which people who become infected are likely to develop a severe case, based on initial symptoms. 

“Look for red flag problems … [including] shortness of breath, or if there’s a possibility of doing an oxygen percentage [test], which could be done either at home or in a doctor’s office,” Campbell said.

An oxygen percentage below 90% is a significant symptom, and would require immediate medical attention. Absent severe symptoms, COVID-19 looks like a lot of other infections, including influenza. 

“But I would always err on the side of contacting health professionals,” Campbell said. 

It’s particularly important to seek help if you have chronic heart, lung or kidney disease, or are elderly, and experience COVID-19 symptoms.

How can someone measure their blood oxygen level? Are phone apps a good method?

Campbell suggested seeking a test from a health professional instead of relying on an app. Tests can be done quickly and easily at a doctor’s office.

“Actually, for people [who] are very, very high risk, like people who already have chronic, severe lung disease, what’s called [a] pulse oximeter is available for purchase at about $40, and would be an excellent tool for those already chronically ill people,” Campbell said.

Web story by Shelly Brisbin.


If you found the reporting above valuable, please consider making a donation to support it here. Your gift helps pay for everything you find on and Thanks for donating today.