11 ms·

Infrared thermometers to screen for Covid: more marketing than medical evidence

114 points by DanBC 6y ago

seesawtron 6y ago
I found the reference [0] more useful to bring home the point made in the article that using these termperature screening devices gives one the false assurance that they can ignore the physical distancing and mask measures. (i) Many thermal cameras and temperature screening products were originally designed for non-medical purposes, such as for building or site security. Businesses and organisations need to know that using these products for temperature screening could put people’s health at risk. (ii) Temperature readings from temperature screening systems will measure skin temperature rather than core body temperature. In either case, natural fluctuations in temperature can occur among healthy individuals. These readings are therefore an unreliable measure for detection of COVID-19 or other diseases which may cause fever. Furthermore, infected people who do not develop a fever or who do not show any symptoms would not be detected by a temperature reading and could be more likely to unknowingly spread the virus. [0] https://www.gov.uk/government/news/dont-rely-on-temperature-screening-products-for-detection-of-coronavirus-covid-19-says-mhra https://www.gov.uk/government/news/dont-rely-on-temperature-...
legerdemain 6y ago
We desperately need cheap and simple means for mass screening of symptoms. On the other hand, I have visited a DHL warehouse to ship some things in the Bay Area recently. Before I can enter, a guard at the door points an infrared thermometer at my forehead. "Eighty-five degrees! Come on in, sir!"
- gruez 6y ago
  >Before I can enter, a guard at the door points an infrared thermometer at my forehead. "Eighty-five degrees! Come on in, sir!" sounds like they used a general purpose infrared thermometer rather than the ones designed for medical use.
  - OrangeMango 6y ago
    We've got an expensive infrared medical thermometer (purchased long before Covid) and it appears to be quite accurate for everyone in our family except me. According to it, I am pretty reliably dead.
- nkrisc 6y ago
  He measured your tempurature as 85 degrees and he didn't even call an ambulance for you? Rude.
  - coding123 6y ago
    Vampires get 10% discount.
henriquez 6y ago
It's security theater, much like the TSA. The temperature guns used at restaurants at gyms seem hard-coded to 97.7F but at least everyone involved can say they were "doing their part" to stop the spread. Whether it works is of secondary importance to making people feel like something is being done, even though in practice there's very little anyone can do.
- edwyr 6y ago
  Theater of the absurd?
- dboreham 6y ago
  Epidemiology Theater
- elliekelly 6y ago
  I had an appointment recently where they took my temperature upon entering the building and the receptionist scribbled the thermometer reading down and circled it at the top of the forms I had to fill out: "28C". Which made me wonder whether she didn't notice that the reading she took was wildly inaccurate or just didn't care. Future historians will wonder why various medical records show people with acute idiopathic hypothermia in the middle of July 2020.
  - chimeracoder 6y ago
    > Future historians will wonder why various medical records show people with acute idiopathic hypothermia in the middle of July 2020. You underestimate how many people in the database (from any time period) will have a recorded body temperature of 0, thanks to weak typing and buggy null coalescence.
  - ACow_Adonis 6y ago
    if it's worth anything, as someone who's worked with lots of manually entered data, i expect to see 0.5% to 5% errors in most publicly sourced data collected in this fashion. i guess what I'm saying is, everyone actually professionally working with such on good faith knows its also stacked with a good proportion of bullshit/error.
raverbashing 6y ago
Yeah this topic is trifle with issues Most common problem: operator error. Are you reading the temperature correctly? Tip, it should not be read directly from the middle of the forehead https://www.seattlechildrens.org/conditions/a-z/fever-how-to-take-the-temperature/ https://www.seattlechildrens.org/conditions/a-z/fever-how-to... If the temperature reads anything lower than 36C, you're doing it wrong and it's very easy for people to get a non-medical IR thermometer, start pointing at people and "checking temperatures" That being said, it seems Covid-19 fevers are usually more intense than flu fevers (even H1N1 ones)
- zoomablemind 6y ago
  Back in the day we purchaised an instant in-ear thermometer, which can also be used for forehead temp. measurement too. The selling point was that with restless baby it's easier to measure the temp. Prior to that we used a common in-mouth (and possibly other side out) kind of beep thermometer. Alright, 15bucks later, I tried it on myself... red alert, fever-fever, when in-ear. Hmmm, roll around forehead -- ambient temp.. The old-fashioned palm-to-forehead -- obviously, no reason for alert. Finally, test with the old in-mouth thermometer- all normal. Reading the instructions only confirmed the unreliable nature of the instant readings. We kept it anyway for "backup", but for practical use continued with the "slow" in-mouth beep-beep, it also helped that it looked like a froglet. Apparently, a success of in-ear measurement is a direct view of the eardrum by the sensor, which is not always possible, esp. with babies.
dgoldstein0 6y ago
I have an infared thermometer I've been using for cooking, and it often gives readings that vary quite a bit. Now some of that is measuring the actual variance of temperature at different points in the pan / pot / etc. But I've also pointed it at myself and got readings that weren't super consistent and definitely weren't core temperature - I think I usually see around 93 on people with it. Generally those readings can vary a few degrees even if you are using it well. It's just not made to measure fractions of a degree. So I was wondering how infrared could possibly work... Not really surprised it doesn't, but the stats at how bad it has been in the past (h1n1, Ebola) are shockingly bad. I guess I was hoping there was some medical variant of these thermometers, which is accurate in the 95-105F range, and the cooking thermometers just sacrificed accuracy for range. But it sounds like that's not the case.
- function_seven 6y ago
  The medical versions are different. They're not just reporting the actual surface temperature of the user's forehead. (Which is going to be a few degrees lower than core body temp) They compensate. I have an iHealth unit that Wyze was selling a few months ago. I check my temperature several times a day. I believe it's quite accurate. In the mornings it'll read 98.2˚F, afternoons I'm at 98.4˚F, and just before bed it'll read either 98.4˚F or 98.6˚F. The fact that it's this consistent with the intraday variation gives me some confidence in it. But, granted, I have yet to have a fever. (That I know of!) I'm not sure what it uses to arrive at the answer. It could be as simple as adding a fixed constant or multiplier to the forehead surface temperature. Or it could separately measure the ambient temperature and factor that into the radiant heat coming from my forehead to arrive at an answer.
  - extrapickles 6y ago
    The medical ones probably only take into account the average emissivity of human skin (which varies somewhat by race/genetics, which they do not account for).
vkou 6y ago
During the start of the COVID pandemic, two of my friends traveled to Florida for a cruse. Naturally, they were quite worried about the prospect of getting on a plague ship in a foreign country. Fortunately, the cruise operator was giving everyone a forehead IR thermometer scan, before letting them board the ship. Unfortunately, at least one person ahead of them in line happened to scan in, and be let on board, sporting a cool temperature of ~85 degrees. I'm not sure if 'body temperature of a two-hour-old-corpse' is a symptom of COVID, but this did not ease my friends' anxieties for the duration of the trip.
tonyedgecombe 6y ago
I’m sure I remember reading that most patients admitted to hospital with Covid don’t have a high temperature.
jdeibele 6y ago
Good to see an article calling this out. Temperature-screening might catch a few people who know that they have a temperature (or are just not feeling well) and are going to "tough it out". Here in the Portland, OR area I've noticed a definite change in how many people are wearing masks. At the grocery store, 2 months ago there were about 5% of the people not wearing masks and they all tended to be men in their 30s and 40s. At convenience stores in more suburban area, I was the only one in a mask. Now it seems like 100% of the people are wearing masks. Wearing masks, not temperature checks, is what seems to be our best option.
- tinus_hn 6y ago
  So your theory is that because most people are wearing masks where before men in their 30s and 40s were not, that seems to be the best option?
  - loco5niner 6y ago
    That's not what they were saying...
    - tinus_hn 6y ago
      So what were they saying? Let’s dissect. > Good to see an article calling this out. Temperature-screening might catch a few people who know that they have a temperature (or are just not feeling well) and are going to "tough it out". The article says that 30000 people were tested. 4 people were false positives, 0 people were true positives. This is called ‘many false positives’. Yet the people who actually had high temperatures were supposed to be at home anyway, right? 4 out of 30000 is not many, they are not real false positives and the design is flawed anyway because people are going to self select, as stated. So the article is just bullshit. Let’s not even go into the rest which tells some unrelated anecdotes about Ebola and other diseases that are not the same diseases and serve nothing but to indicate vague trends under the guise of evidence. > Here in the Portland, OR area I've noticed a definite change in how many people are wearing masks. At the grocery store, 2 months ago there were about 5% of the people not wearing masks and they all tended to be men in their 30s and 40s. At convenience stores in more suburban area, I was the only one in a mask. Now it seems like 100% of the people are wearing masks. This is a completely unrelated tangent. According to this anecdotal non evidence mask use has increased among some stereotyped group and in some establishments. Even if taken at face value this tells nobody anything about the effect of the masks. > Wearing masks, not temperature checks, is what seems to be our best option. That’s an opinion, based on nothing, which even if assumed true means nothing. To the writer something seems to be the best option. That’s fine and maybe it even is the best option. But does it really help to announce they jumped on the mask bandwagon before ‘men in their 30s and 40s’ and people in ‘convenience stores in more suburban area’?
EvanAnderson 6y ago
A Customer of mine is installing an "AI-based temperature screening system"[1]. It's retailing for over $3K. Based on the manual it looks like a facial recognition access control security product (it can interface with the industry standard Wiegand protocol) with an infrared thermometer bolted on and a bunch of gross profit thrown in for good measure. The manual has the look of being a product rushed to market. https://www.richtech-ai.com/product-page/aatss-v2-pro-enterprise https://www.richtech-ai.com/product-page/aatss-v2-pro-enterp...
- makomk 6y ago
  Presumably the "AI" part is that it knows not to set off an alarm if the person's cup of coffee has a fever, as has apparently happened at automated temperature screening points in China.
- fuzzy2 6y ago
  Oh yeah, I also had a technology evaluation on the job on this very topic. It's impressive how entirely inadequate IR cameras are. Glasses, no glasses, tilted head, hot food, ... Sadly, we never got to the facial recognition stage because the client decided they didn't want to support it.
makomk 6y ago
Not just marketing, but also politics. For example, early on in the pandemic, the Chinese government launched a push to reframe their response as a shining example for the rest of the world rather than a failure - and at the heart of this propganda effort was a publication explaining their approach so others could copy it, which claimed the whole thing was founded on mass IR thermometer screening to find people to test. (The document did not appear to be an accurate description of how China actually suppressed Covid-19.) The WHO then jumped on this, doing a tour of major Western publications to amplify China's claims. Journalists and politicians in Western countries also then merrily lept on this to go after governments they disliked, pointing at the lack of IR temperature screening to claim that their governments weren't taking it seriously like those in places like China.
- detaro 6y ago
  > Journalists and politicians in Western countries also then merrily lept on this to go after governments they disliked, pointing at the lack of IR temperature screening Curious, where did you see this? I can't remember seeing anything like that (but that's not to suggest it didn't happen)
- javagram 6y ago
  This is a nice sounding story but I don’t think it’s true. There were already publications from China in early February stressing that tracing the virus via symptomatic cases alone would not be enough to stop the spread. Here’s one from Feb 11. https://www.medrxiv.org/content/10.1101/2020.02.07.20021154v1 https://www.medrxiv.org/content/10.1101/2020.02.07.20021154v... China suppressed the virus not by IR scanning but by a well publicized system of travel restrictions and contact isolation/quarantine of anyone who had been in contact with a known case, regardless of whether they had a fever or other symptoms. All this was public knowledge in February and can be verified by reviewing preprints and news articles from then.
sandworm101 6y ago
Had a long conversation with my dog's vet about these thermometers. He used one I had not seen before, an intra-eye thermometer. It measured the temperature through the eye, the temperature based on light from the dog's optic nerve/retina. That is as close to the brain as one can get without cutting holes. Too bad it isn't allowed for humans yet. It isn't hard to understand his difficulty with normal infrared thermometers: they don't work through fur. But in all animals (us included) temperature can vary many degrees depending on where it is measured. The face/forehead is not the best place if you are looking for 'core' temp. People with reduced blood flow (ie heart disease) will have much cooler foreheads. They may have a fever but their foreheads could appear rather normal.
- nextaccountic 6y ago
  > Too bad it isn't allowed for humans yet. Why is that? Is there any danger?
  - sandworm101 6y ago
    I don't see any dangers, it is just a sensor detecting infrared light, but getting a device "human rated" is a complex process. There might not be a sufficient market to justify an $90 thermometer for humans. Here is a similar device, with a picture of it being used on a dog: https://www.reichert.com/product_details.cfm?skuId=3125&skuTk=1065101262#.XyiNix-YXLk https://www.reichert.com/product_details.cfm?skuId=3125&skuT... The scatter plots of eye/ear/rectal temperature in this article are on point to the covid situations. Variations of +/- several degrees are observed, showing that IR temperature scans might be less than useful in detecting mild fevers. (Also, stubborn cat refusing to open eyes) https://www.theveterinarynurse.com/research/article/investigating-the-use-of-non-contact-infrared-thermometers-in-cats-and-dogs https://www.theveterinarynurse.com/research/article/investig...
  - tgsovlerkhgsel 6y ago
    My guess would be "not certified to be accurate enough for a medical diagnostic tool".
war1025 6y ago
I concluded a long time ago that most of the response to Coronavirus boils down to "security theater". There is a subset of the population that wants to be told that whoever is in charge is "doing something." Compliance with that "something" never seems high on the list. Honestly, some people seem to like that as it gives them something extra to gripe about.
- Tagbert 6y ago
  There is another subset of the population who’s response to the threat is to deny the risk, accuse others of living in fear and pretending that it is a hoax.
  - war1025 6y ago
    Indeed. Stupid comes in many flavors.
MistahKoala 6y ago
'Hygiene theatre' is the term some have settled on for the proliferation and implementation of this kind of thing: https://www.theatlantic.com/ideas/archive/2020/07/scourge-hygiene-theater/614599 https://www.theatlantic.com/ideas/archive/2020/07/scourge-hy... (subsequently posted to the SSC subreddit: https://www.reddit.com/r/slatestarcodex/comments/hzily8/beware_of_hygiene_theater https://www.reddit.com/r/slatestarcodex/comments/hzily8/bewa...)
e40 6y ago
The elephant in the room: my org tried a bunch of them and none of them (even the expensive ones) were at all reliable. If you're trying to discern between 98.6F and 100F... they were useless for that.
wtracy 6y ago
Just thinking out loud: Wouldn't it be possible to get much more accurate temperature readings by having people open wide and imaging the backs of their throats? This could still be done at a reasonable distance. Of course, that would require people to stop long enough to take a reading, and would be useless for the products trying to scan crowds with an unattended camera and AI. And, of course, nothing is really going to help you if the thermometers are inaccurate to begin with.
- LeifCarrotson 6y ago
  Yes, it does get much better accuracy. My company is developing temp screening/survey answering entry kiosks, we've put a lot of effort into getting higher accuracy than the generic imported kiosks. Forehead temperature is highly variable with ambient conditions - sweating while walking in reduces surface temperature, but sitting in a low-humidity air-conditioned car with your face in the morning sun increases it. After as little as 60 seconds in a conditioned space, though, skin surface temp is pretty much normalized. The camera scanners are using Flir microbolometers, which have a huge amount of noise/calibration variation, even on a per-pixel basis. The handheld guns and kiosks which require alignment are using thermopile sensors work much better for employee check-in, they have like a 1:10 spot size so you need to be within a foot or so of the sensor and intentionally align yourself with the sensor. The reading takes about 2 seconds to align and measure, which is fine for clocking in but, as you said, doesn't work in a crowd.
- knodi123 6y ago
  > Wouldn't it be possible to get much more accurate temperature readings by having people open wide and imaging the backs of their throats Old-fashioned oral thermometers warn that they'll be inaccurate if you've drunk a hot or cold beverage recently. I imagine back of the throat thermometers would have the same flaw?
- mindslight 6y ago
  Most people put their masks on well before the entrance. Removing them at a choke point, in the presence of screeners who come into contact with hundreds of people each day, would be stupid. I would only submit to this if it were done outside in open air (not an enclosed lobby) from 10+ feet away.
aaron695 6y ago
But I think it effectively scares people to stay at home. I remember having a hell of a fever during H1N1 going through a airport being scared they would catch me and I'd have to quarantine. Because it was continue or get stuck I continued, if it was just walking into a store....
svrb 6y ago
As someone with a documented medical issue which results in occasional fevers, but is dangerous to no one but myself, I absolutely will throw a fit if I'm ever denied entrance to anywhere on account of such a fever, and I'm not ashamed to admit it. Everyone else in this thread seems to be focusing on the problems with the probability of fever given that someone's infectious, when the real question is the probability that someone is infectious given that they have a fever, which might be due to anything else. But medical discrimination is okay in 2020 I guess.
deleted 6y ago
[deleted]
pvaldes 6y ago
That was a pretty obvious theater. I know a case of people being positive just by driving in a hot day. All days are hot here, at this period of year. Unless you are literally on fire, Is an useless piece of junk Wearing masks on the other hand is not a solution if people does not respect spacing. The disease is stoppable only by vaccines at this moment. Most of us will catch it before that. This is the reality.

114 points by DanBC 6y ago

I found the reference [0] more useful to bring home the point made in the article that using these termperature screening devices gives one the false assurance that they can ignore the physical distancing and mask measures. (i) Many thermal cameras and temperature screening products were originally designed for non-medical purposes, such as for building or site security. Businesses and organisations need to know that using these products for temperature screening could put people’s health at risk. (ii) Temperature readings from temperature screening systems will measure skin temperature rather than core body temperature. In either case, natural fluctuations in temperature can occur among healthy individuals. These readings are therefore an unreliable measure for detection of COVID-19 or other diseases which may cause fever. Furthermore, infected people who do not develop a fever or who do not show any symptoms would not be detected by a temperature reading and could be more likely to unknowingly spread the virus. [0] https://www.gov.uk/government/news/dont-rely-on-temperature-screening-products-for-detection-of-coronavirus-covid-19-says-mhra https://www.gov.uk/government/news/dont-rely-on-temperature-...

legerdemain 6y ago

We desperately need cheap and simple means for mass screening of symptoms. On the other hand, I have visited a DHL warehouse to ship some things in the Bay Area recently. Before I can enter, a guard at the door points an infrared thermometer at my forehead. "Eighty-five degrees! Come on in, sir!"

gruez 6y ago
>Before I can enter, a guard at the door points an infrared thermometer at my forehead. "Eighty-five degrees! Come on in, sir!" sounds like they used a general purpose infrared thermometer rather than the ones designed for medical use.
- OrangeMango 6y ago
  We've got an expensive infrared medical thermometer (purchased long before Covid) and it appears to be quite accurate for everyone in our family except me. According to it, I am pretty reliably dead.
nkrisc 6y ago
He measured your tempurature as 85 degrees and he didn't even call an ambulance for you? Rude.
- coding123 6y ago
  Vampires get 10% discount.

henriquez 6y ago

It's security theater, much like the TSA. The temperature guns used at restaurants at gyms seem hard-coded to 97.7F but at least everyone involved can say they were "doing their part" to stop the spread. Whether it works is of secondary importance to making people feel like something is being done, even though in practice there's very little anyone can do.

edwyr 6y ago
Theater of the absurd?
dboreham 6y ago
Epidemiology Theater
elliekelly 6y ago
I had an appointment recently where they took my temperature upon entering the building and the receptionist scribbled the thermometer reading down and circled it at the top of the forms I had to fill out: "28C". Which made me wonder whether she didn't notice that the reading she took was wildly inaccurate or just didn't care. Future historians will wonder why various medical records show people with acute idiopathic hypothermia in the middle of July 2020.
- chimeracoder 6y ago
  > Future historians will wonder why various medical records show people with acute idiopathic hypothermia in the middle of July 2020. You underestimate how many people in the database (from any time period) will have a recorded body temperature of 0, thanks to weak typing and buggy null coalescence.
- ACow_Adonis 6y ago
  if it's worth anything, as someone who's worked with lots of manually entered data, i expect to see 0.5% to 5% errors in most publicly sourced data collected in this fashion. i guess what I'm saying is, everyone actually professionally working with such on good faith knows its also stacked with a good proportion of bullshit/error.

raverbashing 6y ago

Yeah this topic is trifle with issues Most common problem: operator error. Are you reading the temperature correctly? Tip, it should not be read directly from the middle of the forehead https://www.seattlechildrens.org/conditions/a-z/fever-how-to-take-the-temperature/ https://www.seattlechildrens.org/conditions/a-z/fever-how-to... If the temperature reads anything lower than 36C, you're doing it wrong and it's very easy for people to get a non-medical IR thermometer, start pointing at people and "checking temperatures" That being said, it seems Covid-19 fevers are usually more intense than flu fevers (even H1N1 ones)

zoomablemind 6y ago
Back in the day we purchaised an instant in-ear thermometer, which can also be used for forehead temp. measurement too. The selling point was that with restless baby it's easier to measure the temp. Prior to that we used a common in-mouth (and possibly other side out) kind of beep thermometer. Alright, 15bucks later, I tried it on myself... red alert, fever-fever, when in-ear. Hmmm, roll around forehead -- ambient temp.. The old-fashioned palm-to-forehead -- obviously, no reason for alert. Finally, test with the old in-mouth thermometer- all normal. Reading the instructions only confirmed the unreliable nature of the instant readings. We kept it anyway for "backup", but for practical use continued with the "slow" in-mouth beep-beep, it also helped that it looked like a froglet. Apparently, a success of in-ear measurement is a direct view of the eardrum by the sensor, which is not always possible, esp. with babies.

dgoldstein0 6y ago

I have an infared thermometer I've been using for cooking, and it often gives readings that vary quite a bit. Now some of that is measuring the actual variance of temperature at different points in the pan / pot / etc. But I've also pointed it at myself and got readings that weren't super consistent and definitely weren't core temperature - I think I usually see around 93 on people with it. Generally those readings can vary a few degrees even if you are using it well. It's just not made to measure fractions of a degree. So I was wondering how infrared could possibly work... Not really surprised it doesn't, but the stats at how bad it has been in the past (h1n1, Ebola) are shockingly bad. I guess I was hoping there was some medical variant of these thermometers, which is accurate in the 95-105F range, and the cooking thermometers just sacrificed accuracy for range. But it sounds like that's not the case.

function_seven 6y ago
The medical versions are different. They're not just reporting the actual surface temperature of the user's forehead. (Which is going to be a few degrees lower than core body temp) They compensate. I have an iHealth unit that Wyze was selling a few months ago. I check my temperature several times a day. I believe it's quite accurate. In the mornings it'll read 98.2˚F, afternoons I'm at 98.4˚F, and just before bed it'll read either 98.4˚F or 98.6˚F. The fact that it's this consistent with the intraday variation gives me some confidence in it. But, granted, I have yet to have a fever. (That I know of!) I'm not sure what it uses to arrive at the answer. It could be as simple as adding a fixed constant or multiplier to the forehead surface temperature. Or it could separately measure the ambient temperature and factor that into the radiant heat coming from my forehead to arrive at an answer.
- extrapickles 6y ago
  The medical ones probably only take into account the average emissivity of human skin (which varies somewhat by race/genetics, which they do not account for).

vkou 6y ago

During the start of the COVID pandemic, two of my friends traveled to Florida for a cruse. Naturally, they were quite worried about the prospect of getting on a plague ship in a foreign country. Fortunately, the cruise operator was giving everyone a forehead IR thermometer scan, before letting them board the ship. Unfortunately, at least one person ahead of them in line happened to scan in, and be let on board, sporting a cool temperature of ~85 degrees. I'm not sure if 'body temperature of a two-hour-old-corpse' is a symptom of COVID, but this did not ease my friends' anxieties for the duration of the trip.

tonyedgecombe 6y ago

I’m sure I remember reading that most patients admitted to hospital with Covid don’t have a high temperature.

jdeibele 6y ago

Good to see an article calling this out. Temperature-screening might catch a few people who know that they have a temperature (or are just not feeling well) and are going to "tough it out". Here in the Portland, OR area I've noticed a definite change in how many people are wearing masks. At the grocery store, 2 months ago there were about 5% of the people not wearing masks and they all tended to be men in their 30s and 40s. At convenience stores in more suburban area, I was the only one in a mask. Now it seems like 100% of the people are wearing masks. Wearing masks, not temperature checks, is what seems to be our best option.

tinus_hn 6y ago
So your theory is that because most people are wearing masks where before men in their 30s and 40s were not, that seems to be the best option?
- loco5niner 6y ago
  That's not what they were saying...
  - tinus_hn 6y ago
    So what were they saying? Let’s dissect. > Good to see an article calling this out. Temperature-screening might catch a few people who know that they have a temperature (or are just not feeling well) and are going to "tough it out". The article says that 30000 people were tested. 4 people were false positives, 0 people were true positives. This is called ‘many false positives’. Yet the people who actually had high temperatures were supposed to be at home anyway, right? 4 out of 30000 is not many, they are not real false positives and the design is flawed anyway because people are going to self select, as stated. So the article is just bullshit. Let’s not even go into the rest which tells some unrelated anecdotes about Ebola and other diseases that are not the same diseases and serve nothing but to indicate vague trends under the guise of evidence. > Here in the Portland, OR area I've noticed a definite change in how many people are wearing masks. At the grocery store, 2 months ago there were about 5% of the people not wearing masks and they all tended to be men in their 30s and 40s. At convenience stores in more suburban area, I was the only one in a mask. Now it seems like 100% of the people are wearing masks. This is a completely unrelated tangent. According to this anecdotal non evidence mask use has increased among some stereotyped group and in some establishments. Even if taken at face value this tells nobody anything about the effect of the masks. > Wearing masks, not temperature checks, is what seems to be our best option. That’s an opinion, based on nothing, which even if assumed true means nothing. To the writer something seems to be the best option. That’s fine and maybe it even is the best option. But does it really help to announce they jumped on the mask bandwagon before ‘men in their 30s and 40s’ and people in ‘convenience stores in more suburban area’?

EvanAnderson 6y ago

A Customer of mine is installing an "AI-based temperature screening system"[1]. It's retailing for over $3K. Based on the manual it looks like a facial recognition access control security product (it can interface with the industry standard Wiegand protocol) with an infrared thermometer bolted on and a bunch of gross profit thrown in for good measure. The manual has the look of being a product rushed to market. https://www.richtech-ai.com/product-page/aatss-v2-pro-enterprise https://www.richtech-ai.com/product-page/aatss-v2-pro-enterp...

makomk 6y ago
Presumably the "AI" part is that it knows not to set off an alarm if the person's cup of coffee has a fever, as has apparently happened at automated temperature screening points in China.
fuzzy2 6y ago
Oh yeah, I also had a technology evaluation on the job on this very topic. It's impressive how entirely inadequate IR cameras are. Glasses, no glasses, tilted head, hot food, ... Sadly, we never got to the facial recognition stage because the client decided they didn't want to support it.

makomk 6y ago

Not just marketing, but also politics. For example, early on in the pandemic, the Chinese government launched a push to reframe their response as a shining example for the rest of the world rather than a failure - and at the heart of this propganda effort was a publication explaining their approach so others could copy it, which claimed the whole thing was founded on mass IR thermometer screening to find people to test. (The document did not appear to be an accurate description of how China actually suppressed Covid-19.) The WHO then jumped on this, doing a tour of major Western publications to amplify China's claims. Journalists and politicians in Western countries also then merrily lept on this to go after governments they disliked, pointing at the lack of IR temperature screening to claim that their governments weren't taking it seriously like those in places like China.

detaro 6y ago
> Journalists and politicians in Western countries also then merrily lept on this to go after governments they disliked, pointing at the lack of IR temperature screening Curious, where did you see this? I can't remember seeing anything like that (but that's not to suggest it didn't happen)
javagram 6y ago
This is a nice sounding story but I don’t think it’s true. There were already publications from China in early February stressing that tracing the virus via symptomatic cases alone would not be enough to stop the spread. Here’s one from Feb 11. https://www.medrxiv.org/content/10.1101/2020.02.07.20021154v1 https://www.medrxiv.org/content/10.1101/2020.02.07.20021154v... China suppressed the virus not by IR scanning but by a well publicized system of travel restrictions and contact isolation/quarantine of anyone who had been in contact with a known case, regardless of whether they had a fever or other symptoms. All this was public knowledge in February and can be verified by reviewing preprints and news articles from then.

sandworm101 6y ago

Had a long conversation with my dog's vet about these thermometers. He used one I had not seen before, an intra-eye thermometer. It measured the temperature through the eye, the temperature based on light from the dog's optic nerve/retina. That is as close to the brain as one can get without cutting holes. Too bad it isn't allowed for humans yet. It isn't hard to understand his difficulty with normal infrared thermometers: they don't work through fur. But in all animals (us included) temperature can vary many degrees depending on where it is measured. The face/forehead is not the best place if you are looking for 'core' temp. People with reduced blood flow (ie heart disease) will have much cooler foreheads. They may have a fever but their foreheads could appear rather normal.

nextaccountic 6y ago
> Too bad it isn't allowed for humans yet. Why is that? Is there any danger?
- sandworm101 6y ago
  I don't see any dangers, it is just a sensor detecting infrared light, but getting a device "human rated" is a complex process. There might not be a sufficient market to justify an $90 thermometer for humans. Here is a similar device, with a picture of it being used on a dog: https://www.reichert.com/product_details.cfm?skuId=3125&skuTk=1065101262#.XyiNix-YXLk https://www.reichert.com/product_details.cfm?skuId=3125&skuT... The scatter plots of eye/ear/rectal temperature in this article are on point to the covid situations. Variations of +/- several degrees are observed, showing that IR temperature scans might be less than useful in detecting mild fevers. (Also, stubborn cat refusing to open eyes) https://www.theveterinarynurse.com/research/article/investigating-the-use-of-non-contact-infrared-thermometers-in-cats-and-dogs https://www.theveterinarynurse.com/research/article/investig...
- tgsovlerkhgsel 6y ago
  My guess would be "not certified to be accurate enough for a medical diagnostic tool".

war1025 6y ago

I concluded a long time ago that most of the response to Coronavirus boils down to "security theater". There is a subset of the population that wants to be told that whoever is in charge is "doing something." Compliance with that "something" never seems high on the list. Honestly, some people seem to like that as it gives them something extra to gripe about.

Tagbert 6y ago
There is another subset of the population who’s response to the threat is to deny the risk, accuse others of living in fear and pretending that it is a hoax.
- war1025 6y ago
  Indeed. Stupid comes in many flavors.

MistahKoala 6y ago

'Hygiene theatre' is the term some have settled on for the proliferation and implementation of this kind of thing: https://www.theatlantic.com/ideas/archive/2020/07/scourge-hygiene-theater/614599 https://www.theatlantic.com/ideas/archive/2020/07/scourge-hy... (subsequently posted to the SSC subreddit: https://www.reddit.com/r/slatestarcodex/comments/hzily8/beware_of_hygiene_theater https://www.reddit.com/r/slatestarcodex/comments/hzily8/bewa...)

e40 6y ago

The elephant in the room: my org tried a bunch of them and none of them (even the expensive ones) were at all reliable. If you're trying to discern between 98.6F and 100F... they were useless for that.

wtracy 6y ago

Just thinking out loud: Wouldn't it be possible to get much more accurate temperature readings by having people open wide and imaging the backs of their throats? This could still be done at a reasonable distance. Of course, that would require people to stop long enough to take a reading, and would be useless for the products trying to scan crowds with an unattended camera and AI. And, of course, nothing is really going to help you if the thermometers are inaccurate to begin with.

LeifCarrotson 6y ago
Yes, it does get much better accuracy. My company is developing temp screening/survey answering entry kiosks, we've put a lot of effort into getting higher accuracy than the generic imported kiosks. Forehead temperature is highly variable with ambient conditions - sweating while walking in reduces surface temperature, but sitting in a low-humidity air-conditioned car with your face in the morning sun increases it. After as little as 60 seconds in a conditioned space, though, skin surface temp is pretty much normalized. The camera scanners are using Flir microbolometers, which have a huge amount of noise/calibration variation, even on a per-pixel basis. The handheld guns and kiosks which require alignment are using thermopile sensors work much better for employee check-in, they have like a 1:10 spot size so you need to be within a foot or so of the sensor and intentionally align yourself with the sensor. The reading takes about 2 seconds to align and measure, which is fine for clocking in but, as you said, doesn't work in a crowd.
knodi123 6y ago
> Wouldn't it be possible to get much more accurate temperature readings by having people open wide and imaging the backs of their throats Old-fashioned oral thermometers warn that they'll be inaccurate if you've drunk a hot or cold beverage recently. I imagine back of the throat thermometers would have the same flaw?
mindslight 6y ago
Most people put their masks on well before the entrance. Removing them at a choke point, in the presence of screeners who come into contact with hundreds of people each day, would be stupid. I would only submit to this if it were done outside in open air (not an enclosed lobby) from 10+ feet away.

aaron695 6y ago

But I think it effectively scares people to stay at home. I remember having a hell of a fever during H1N1 going through a airport being scared they would catch me and I'd have to quarantine. Because it was continue or get stuck I continued, if it was just walking into a store....

svrb 6y ago

As someone with a documented medical issue which results in occasional fevers, but is dangerous to no one but myself, I absolutely will throw a fit if I'm ever denied entrance to anywhere on account of such a fever, and I'm not ashamed to admit it. Everyone else in this thread seems to be focusing on the problems with the probability of fever given that someone's infectious, when the real question is the probability that someone is infectious given that they have a fever, which might be due to anything else. But medical discrimination is okay in 2020 I guess.

deleted 6y ago

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pvaldes 6y ago

That was a pretty obvious theater. I know a case of people being positive just by driving in a hot day. All days are hot here, at this period of year. Unless you are literally on fire, Is an useless piece of junk Wearing masks on the other hand is not a solution if people does not respect spacing. The disease is stoppable only by vaccines at this moment. Most of us will catch it before that. This is the reality.