Health Life

Temperature scanners aren’t good at telling who has COVID-19—here’s how to fix that

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During the pandemic, the chances are that as you enter an airport or doctor’s surgery, someone will point an infrared thermometer at your forehead in order to assess your temperature. Your skin temperature is being measured to try to identify whether or not you have an increased deep body temperature, which is indicative of fever, one of the leading signs of COVID-19.

The good thing about using infrared thermometers is that they are quick, simple and non-invasive. You can rapidly screen many people without inconveniencing them, for instance travelers moving through an airport or people entering a sports stadium. But to be useful mass-screening tools, infrared thermometers also need to be accurate—and this is where problems arise.

Although is a leading symptom of COVID-19, many don’t have any symptoms, or they develop a fever after they have become infectious, got ill and entered hospital. At least 11% of those with COVID-19 do not have a fever, and only 43% of patients ill enough to be admitted to hospital have one. So, looking for fever is not a foolproof approach.

Plus, while an infrared can measure accurately, the real question is: does forehead tell us anything about deep temperature, the true sign of fever? In certain, highly controlled circumstances, an increased forehead temperature can indicate a raised deep body temperature—this is why people put their hand on your forehead when you say you don’t feel very well.

But the problem is, forehead or skin temperature can be increased or decreased independently of deep body temperature, for many reasons. Having just been in a cold or hot environment, sunburn, having just exercised, wearing too many clothes, having drunk alcohol, having just eaten, having a variety of skin conditions—these can all influence skin

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COVID-19 virus test: MedlinePlus Medical Encyclopedia

Testing can be done in a couple of ways. For a nasopharyngeal test, you will be asked to cough before the test begins and then tilt your head back slightly. A sterile, cotton-tipped swab is gently passed through a nostril and into the nasopharynx. This is the uppermost part of the throat, behind the nose. The swab is left in place for several seconds, rotated, and removed. This same procedure may be done on your other nostril.

For an anterior nasal test, the swab will be inserted into your nostril no more than 3/4 of an inch (2 centimeters). The swab will be rotated 4 times while pressing against the inside of your nostril. The same swab will be used to collect samples from both nostrils.

Tests may be done by a health care provider at an office, drive-through, or walk-up location. Check with your local health department to find out where testing is available in your area.

At-home testing kits are also available that collect a sample using a either nasal swab or sample of saliva. The sample is then either sent to a lab for testing, or with some kits, you can get results at home. Contact your provider to see if home collection and testing is appropriate for you and if it is available in your area.

There are two types of virus tests available that can diagnose COVID-19:

  • Polymerase chain reaction (PCR) tests detect the genetic material of the virus that causes COVID-19. The samples are usually sent to a laboratory for testing, and results are available in a few days. There are also rapid PCR diagnostic tests that are run on specialized equipment on-site, for which the results are available immediately.
  • Antigen tests detect specific proteins on the virus that causes COVID-19. Antigen tests are