Question for those in the know, today I was scheduled for a minor procedure and upon arriving at the hospital I took my hat off so they could use the forehead thermometer and it was a little high, 99.1 but they attributed it my wearing a hat. Four hours later they wheel me into surgery and again they took my temperature and it came back at 101.9 so they waited a few minutes and took it again and it was at 101.4 so they decided to delay the surgery due to COVID concerns. Seemed like a valid reason so I agreed to reschedule and left without delay. I feel completely fine, so I decided to check my temp using the two thermometers I have at home and I was at 97.8, my usual temperature. Needless to say I wasn't happy about wasting half my day at the hospital but my question is, how accurate are those forehead thermometers? The reason I'm posting this here is I've read that a lot of places will require the use of these forehead scanners before entering a business, sporting event, airport etc. Taking my temperature numerous times orally and under the arm pit and all within normal ranges, how could the forehead thermometer be so wildly different?

In my experience, they are usually too low versus too high, especially if they caught it high 3 different times. I work at a preschool and routinely all the kids turn up 96-low 97.

Did they COVID test you prior to surgery?

No, but if your experience is more typical I'd tend to think there is was something up with their reader because based on past experience if I had a fever of 101.9 I would know it.

I've been checked at the gym about six days a week since mid-June and have been 97.3 to 97.7 every time.

I have had experiences before where my face just felt flushed and would pop around 101 on a forehead thermometer but would read normal both orally and underarm. Usually my forehead temp would drop over the next 15-20 minutes.

The hospital is about the first place I've had to wear a mask since all this started and it was tripping my anxiety which was causing me to hyperventilate so maybe that had something to do with it

That happened to me as well. First time I had to wear a mask somewhere, and it caused a lot of anxiety, plus it was really hot. They scanned me and it was around 100.8. Checked when I got to the car about an hour late and my ear thermometer also read around 100.8. After a 30 minute mask-free drive home, I was back to 97.7.

So your forehead is not your actual core temperature. This no-contact thermometers aren't directly displaying your foreheads actual temperature, they're getting your foreheads temperature and then doing some math and converting it to an equivalent oral temperature.

So if you go for a run, or you get out of the shower,there's sweat on your forhead, you've been standing in the sun, it's very windy outside, etc., this can all affect the accuracy of the reading as they all affect the surface temperature and throwoff the formula used to convert to a useful oral equivalent temperature. It's all calibrated in a lab environment with people likely sitting at rest in a temperature controlled room and dry foreheads.

They're a screening tool at best. Not a diagnostic tool.

We use them and usual off by 1.5 up to 2 degrees on low side. Ambient air and calibration can cause issues. But not sure why the hospital isn't using oral thermometer with a disposable plastic sheath.

I had surgery in November, they did the IR to get in the hospital, but once I got to my presurgery room and and post op regular room nurse did the disposable temperature.

bigtruckguy3500 said:

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They're a screening tool at best. Not a diagnostic tool.

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This was kind of the main point that I asked about these on this board. I have read that a lot of office buildings and airports plan to implement the forehead scanners, I hope they don't immediately deny you entry based on a testing method that can be thrown off by environmental conditions

From our experience as lay people, we have had a lot of issues with them. The wife and I typically show up on the lower side which is no problem. However, 93-year-old mother in law will typically be on the higher side when we try to check her back into her assisted living facility. Particularly had issues this summer when it was hot. We learned to sit her in front of the vehicle a/c for a few minutes and then get her inside as quickly as possible. She'd test fine then. Otherwise, she would have a reading of 101 or, one occasion, over 102. I have no trust in those and would think that a medical facility would use a real thermometer if there was a question.

The building where I work has been doing this for months, and my small group fitness class did it for a while.

No one was automatically denied entry. You would be told to go stand in the corner for a few minutes until you "cool off" and give a normal reading.

It was an issue in the summer, because people would leave and go for a walk or get in their hot car, and obviously their temps would be elevated. Or, if you had glasses on, it might detect the temp of the metal or plastic frame rather than the temp of your body.

Occasionally the thing would measure someone's temp as something absurd like 105*.

I have my doubts about how useful temp data really is. After my experience, I think we should have to pass a smell test.