Body Temperature - What You've Been Taught is Wrong! (Strong Exam)

A discussion of the assessment and interpretation of body temperature, including problems with thermometer inaccuracies, and common myths about normal temperature and the definition of a fever.

@0:00 Introduction
@0:31 Thermometers and their accuracy
@4:21 Normal range of temperature and definition of a fever
@10:38 Etiologies of fevers and hypothermia
@12:06 Common pitfalls/mistakes

References:

Cutuli SL, et al. Accuracy of non-invasive body temperature measurement methods in adult patients admitted to the intensive care unit: a systematic review and meta-analysis. Crit Care Resusc. 2023; 23:6-13.

Niven DJ, et al. Accuracy of peripheral thermometers for estimating temperature. Ann Intern Med. 2015;163:768-77.

Sund-Levander M, Forsberg C, Wahren LK. Normal oral, rectal, tympanic and axillary body temperature in adult men and women: a systematic literature review. Scand J Caring Sci. 2002; 16:122-8.

Protsiv M, et al. Decreasing human body temperature in the United States since the industrial revolution. Elife. 2020;7:9:e49555.

Pecoraro V, et al. The diagnostic accuracy of digital, infrared and mercury-in-glass thermometers in measuring body temperature: a systematic review and network meta-analysis. Intern Emerg Med. 2021; 16:1071-83.

Mah AJ, et al. Studying the accuracy and function of different thermometry techniques for measuring body temperature. Biology. 2021; 10:1327.

Mackowiak PA, Wasserman SS, Levine MM. A critical appraisal of 98.6 degrees F, the upper limit of the normal body temperature, and other legacies of Carl Reinhold August Wunderlich. JAMA. 1992; 268:1578-80.

Mackowiak PA, Worden G. Carl Reinhold August Wunderlich and the evolution of clinical thermometry. Clin Infect Dis. 1994; 18:458-67.

#physicalexam #osce

[StrongMed]

Frustratingly, there was an on-screen typo in the first version of this video that I published 18 hrs ago. It may have been a minor issue, but if I didn't fix it, it would annoy me every time someone commented on it in the future. Thus, here is the corrected version. Thanks to @ellertt for pointing it out.

There's still a great (IMHO) one-off video coming next Sunday, which as I posted before, has cameos from my 2 favorite people in the world! (And definitely has no typos in it)

[trishoconnor]

I have hypothyroidism, and even with medication, my temperature is rarely above 97°F, often 95° or even a bit lower. (95° is usually considered hypothermia.) I have often had the experience of health care professionals who were not already acquainted with me looking at the thermometer and saying "That can't be right, " until I tell them I typically run low. I can tell a lot about how helpful they will be to me from how seriously they take my report of my experience. Fortunately, when I was diagnosed with Hodgkins Lymphoma (since cured), my oncologist and his nurses were very good about listening to the patient and putting those self-reports into the big picture. When I first started chemo, they told me their usual rule of thumb for what temperature to call, 24/7 (I think 101°). I asked if it should be any different given my tendency to "run low, " and after checking my recent measurement, they settled on 99° as my "call the doctor" temp while on chemo. By the way, I've done immersion in a cold pool and my temp measured as low as 92.4°, and I was still not showing the other signs of hypothermia like clumsiness or confusion. Apparently, my body has gotten pretty used to being cold!

[GoodDogIda]

What a blessing this video is!
A few weeks ago a vsauce short (are people getting hotter? No, they’re getting colder.) video stuck the question in my brain and I couldn’t for the life of me find anything that I could conclusively take as relevant information. It’s so difficult to have hyper specific obscure questions about a field you know nothing about, I am so glad to have ran into this video by complete coincidence.
I was sent to your channel by HTCT Ann Reardon, band I am leaving a comment and liking this video to let the algorithm know!
Cheers!

[andreafeelsfantastic]

Validation! I have felt before like I had a fever with chills and aches and just feeling feverish, but my actual temperature in the 99F point something range and so was too low for anyone to label it that way!

[lmagoddess]

This is so true. Early in covid my work set up a temp guideline of 99.5 F as not allowed to work. Seemed reasonable, until I went in to work and was winded climbing stairs but had a temp of 95.4, so I started work. I felt a little off and a coworker said I didn't look normal. He said I looked "pale but red cheeked." Went back up stairs to HR and couldn't catch my breath but temp was the same so HR gave me the choice of staying or getting tested.
My temp went down to 98 something and the clinic nurse was flat rude when I told her my temp runs 1-2 ° low. "That's what everyone says, but at least you got out of work for a few hrs, right?" Her sneer made it clear she wasn't joking. She also was rough with the swab and had both sides of my nose bleeding and me yelling at her from the pain. She "yelled back it wasn't that bad!" And left to run the test. She did not return but the clinic doctor did, she gave me tissues for my bloody nose and explained that I yes I did test positive for covid and also influenza A. She even apologized for the nurses behavior. I must have been running on adrenaline because by the time I had arrived home I felt like death warmed over.

[KatielouSweetlove-in]

As a patient who has told Dr's repeatedly that my temperature (by the old style but safer non mercury oral thermometer) is generally 36.4°C and therefore 37.5 is a fever to me and been told they only go by the standard 37°C despite me also explaining to them that as I'm also chronically ill which also tends to lower temperature I very pleased to see you cooborate this. I shall point my GP who is the head GP of the group practice to this YouTube video for further education of their Dr's. I have also seen in clinical practice in hospital settings thermometers used that said I had a temperature of 32°C when I felt perfectly fine had normal skin temperature and looked a normal colour and they still didn't question it and wrote it in my notes ! 😂 the Dr's then had several fits of anxiety when reading the charts and had this flagged I told them they had a faulty thermometer and if theyd checked I they'd have found my temperature normal when the junior Dr was sent rushing up to see me.

[julietravis]

I’ve said this for years, even said we should use the mom test which is side of cheek or back of their had as a back up because those are at least a better sense of excessive heat.

And checking the automatic blood pressure to a manual one will make the hair on the back of your neck stand up!

[gregoryrichter]

I think I know the topic of my upcoming master thesis now :) thanks Dr. Strong

[alakborwen]

My normal temperature usually runs around 96.8F (I was curious on one of my vacation weeks a few years ago and took my temperature three times a day (8am, noon, and 8pm) and then took the average of that and got the 96.8. Whenever I go to the doctor with a fever (usually I’ll wait to see if it gets up to 99.9 before I go) I usually have to argue with the person taking my temperature when they tell me I don’t have a fever, they never want to listen to me when I try to explain that my temperature runs low. It gets very annoying when I’m not feeling well.

[karenmsuk]

Baseline readings are something I do at home, same site, same thermometer, same time of day. I drive my daughter nuts but she has tri and bigeminy so her stats need to be tracked no matter what our last ER doctor told me.

[jayaramchandrasekar]

Great video thanks! I'm definitely guilty of thinking about fever as only 100.5 F and you bring a great argument to change that behavior and trust our patients who have a lower temp

[hvymtal]

At my ambulance company we use the no-contact style. I swear half of them read somewhere between 97.3 and 97.6 F regardless of where you take the temp or what the actual peripheral temp is.

[mikeh]

as always well presented and precise, thanks of that

[carolerparks]

This variance in temps with different thermometers can be more serious. Recently my daughter checked her 5 year-olds temp with digital oral, no-contact & with ear tympanic. The results were 103 to 106. Of course I stressed to her to get it lowered as quickly as possible, then off to Urgent Care. I sure wish the perimeters for obtaining accurate readings, were clearer.

[anthonybevers]

The only time I was not hypothermic on a no touch thermometer was when I had a 104 fever (oral) when I got dengue. My temp then was 98.3 on that no touch device.

[mopeyhat]

If you can't find any other documentation on the thermometer's reported accuracy, I wouldn't be surprised if it was coming straight from the technical specs of the thermister or other sensor

[alirezazakaie]

Thank you...we are waiting for new videos

[jessynachobusiness]

Currently sick. My normal body temperature runs about 96-97. Now I’m at 98.7 feeling terrible. I hate being told I don’t have a fever while freezing and aching like I have one…

[KatielouSweetlove-in]

At a covid vaccination centre one man used the point and click temperature gun and I think three of us had temperatures of 32 °C or less he was meant to be checking that no one turned up with a fever as he stood with the gun more than 12 inches away from the patient then stood like he was firing an actual gun I suspect what he got was mostly the air temperature. Its no wonder numerous people I knew that caught covid did so when attending a covid vaccination line up stood too close up in waiting lines to get everyone in the building because of cold weather. I noticed that this was mostly the case in the winter/ early spring vaccination or late autumn boosters when the temperature dropped and then the people going ended up squashed into places that were swelteringly hot esp. Compared to the outside temperature as the staff inside didn't want to be fold or be affected by the doors opening for patients to attend as most places had no lobby to help prevent the heat going out but the heat then helped the bacteria/virus replicate and transmit on top of dodgy thermometers and people not realising that tge 'slight cold' they thiught they had wax actually covid as not many people actually thought to self test prior to going out which has only gotten worse now that the vast majority now think covid is no longer a problem and they don't have to do anything about it and think its akin to a cold and most have stopped getting the annual booster offered in the UK because of this attitude apart from Boris Johnson (pm) before leaving post told everyone thry Jo longer had to do any of the preventative actions or think of other people especially the most vulnerable that was tge whole point of all the lockdowns. So between the faulty thermometers and misuse in clinical settings including misinformation about temperature being one standard which all are put against and dismissed its no wonder more people end up in hospital because more was missed when prevention could have helped the patient. While the core temperature thermometers are not practical in normal GP practices a temperature taken with digital oral thermometers regularly as a screen as BP readings done and plotted could easily with a tick chart to check against other signs of infection also to mark on the chart would give an individual marker as to where that person has their normal temperature and then add about 1-1.5°C to find their personal fever marker but also should be only incojection to other signs of illness that can cause fever. It shouldn't be hard to do nor should the software.

[kowalskiplota]

I cannot imagine any adult, medical professional and patient alike, that would accept the insertion of a thermometer to the rectum for the sake of accuracy or for the sake of anything at all. What should I do? I am a first year resident and you have been lifesaver of my carreer and my patients alike.