It’s Getting Hot in Here: Body Temperature

How many times have you had your temperature taken lately? I think I’ve had my temperature taken thousands of times in the last few months. We are seeing the increased use of forehead scanning thermometers and temporal scanners, all the non-contact forms of temperature assessment, to screen folks for COVID-19 symptoms upon entry to any public space. Are you taking temperatures in your PT clinic? I hope so. It’s not a perfect assessment, but it’s better than nothing and at least gives the appearance of attempting to create a safe patient environment.

There’s a few considerations for temperature that can be really relevant to PT practice outside of just making sure your patients don’t have COVID-19. That’s right, ya’ll! We are going back to our old friend, Sepsis. We talked about sepsis in quite a few posts in the past, and it keep rearing it’s super ugly head in so many topics. You may be thinking, “Doctor B, I really don’t see that many patients with sepsis, so I’m not sure where you are going here…” I may be the odd one out, but I’ve seen too many patients with sepsis. Even one is too many, but I’ve seen far too many. I wouldn’t challenge you that, depending on your setting, you’ve probably seen more patients with sepsis than you realize. If you are in general acute care, skilled nursing, or home care, sepsis is everywhere, but it takes on different names, usually the names of the infectious entities that cause it.

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I’m sure you’ve heard of all the infections that land people in the hospital for “pneumonia”, clostridium difficile (c. diff), MRSA, VRSA, “staph”, etc…… All of these land people in the hospital because they have, to some point, gone septic, meaning the pathogens have entered the blood stream (aka bacteremia, septicemia, blood poisoning) making them far more difficult to fight off without help. But, as PT’s how do we detect sepsis? If you read the headliner on this article, you should probably have an idea of where I’m going.

Detecting sepsis and other infections is a top priority job for PTs and other rehab professionals. He look for signs and symptoms of infection all the time, from redness and swelling to exudate and smell. But infections can be so much more subtle than that. And sepsis can be hidden.

The Basics

Remember that human beings can only function properly in a certain homeostatic environment. Just like our pH range is so small (7.35-7.45 ideal range), our temperature range is also pretty narrow: 96.0 F to 100.4 F. Obviously, that doesn’t mean we can’t somewhat function outside of these parameters, but the function is not ideal.

That’s right, normal temperature is a range. It’s not just 98.6 F. That’s because “normal” depends on where an dhow the reading was taken. Temperature can be taken at any of the following locations, but be sure to document the location as there are different “normal” temperatures for each location.

  • Oral/Sublingual
  • Temporal
  • Ear
  • Axillary
  • Forehead
  • Rectal
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Not to say that any one is better than the other as they all have their clinical place, but some are more accurate. However, it may be significantly difficult to get an accurate oral temperature on a screaming infant. And most adults will shy away from a rectal thermometer. So, even though they differ in accuracy, they can all be useful. Clearly, even though forehead scanning is one of the least accurate, it has its place in the new “contact-less” environment in which we function.


So, what if a body temperature is below 96.0 F? Remember that body temperature elevates to ward off invaders. It is part of our body’s immune response. If the temperature doesn’t respond to invaders, the body is NOT fighting. Sometimes, the temperature can even decrease. I have actually had a patient where a sublingual temperature of 95.2 F was his only symptom of sepsis because his body was NOT fighting the infection and we caught it early. A decline in body temperature can happen for a number of reasons:

  • Advanced age resulting in less efficient immune function
  • Multiple infections overwhelming the immune system
  • Overload of antipyretic medications (acetaminophen, ibuprofen, some antihypertensives…)
  • Certain genetic conditions (Prader-Willi Syndrome)

Consequently, the list ofd things that makes someone more susceptible to septic infections looks pretty similar with the addition of:


AKA Fever. However, hyperthermia can happen for reasons other than infection such as with heat stroke. This is also something we need to be monitoring in our patients as we may be asking them to physically exert themselves, whether in our presence or not, through exercise on a hot day. We may also see patients who have a host of thermoregulation conditions that can be caused by:

Remember that an elevation in body temperature is a response to an infectious agent of some kind. Invaders tend to only be able to live in certain environments so the body elevates the temperature to change the environment and make it unfavorable or uninhabitable for the invader. Elevation of body temperature can also happen in the evenings as your body begins its “clean-up” process. However, most medical professionals don’t consider elevated body temperature to be febrile until it is 100.5 F or greater.

Clinical Application

If you are taking a full set of vitals anyway, blood pressure, heart rate, oxygen saturation, you may as well take a temperature, too. Especially right now, temperature matters and is important to our fully informed treatment of any patient. However, if you have someone who is post-operative of ANY KIND, you should be taking their temperature at your visits. We are the front line against infections in our post-operative patients.

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And in our treatment of populations on either end of the age spectrum, we need to constantly be putting sepsis on the list when we consider our differential diagnosis. I’m not saying it needs to be front and center, butI’m not saying it shouldn’t be, either, especially given the pandemic climate. This also then feeds in to the ongoing screening of people for COVID-19 and other infections that we discussed HERE.

How many COVID-19 screenings have you done in the past week? Tell me in the comments!


CDC. (2020). Sepsis. Retrieved from

HealthWise Staff. (2019). Fever Temperatures: Accuracy and Comparison. C.S. Mott Children’s Hospital, University of Michigan Medicine. Retrieved from

Skelton, F. (2016). Rehabilitation of Central Nervous System Disorders: Impaired Thermoregulation. American Association of Physical Medicine and Rehabilitation. Retrieved from

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2 thoughts on “It’s Getting Hot in Here: Body Temperature

  1. I work in a hospital and do the temperature on everyone walking through the front door some days. So, I take hundreds of temperatures on average. The temps vary greatly with the different thermometers. We use the forehead lazer pointer mostly. If I have a really unusual off temp with that then I will retake with the temporal scanner type or vise versa.
    A couple issues that have come up. First, people are now concerned about their Pineal gland being affected by the lazer. And, second, the fear that children are being desensitized to something being pointed at their heads in such a way that should call upon the autonomic system. Do you have any elaboration on these topics?


    1. Sure, a few thoughts. As far as children being desensitized, I don’t think it’s a bad thing that children are getting used to having medical professionals take their temperature in different ways. Having “something” pointed at their head could be just about anything and not all thermometers are shaped like weapons. I don’t see anything wrong with the child’s adult explaining to the child that their health and safety are important and taking their temperature is part of that.
      As far as the effects on the deep brain, not likely. These thermometers are measuring only surface temperatures. And, as someone who takes a lot of temperatures, I’m sure you often see the effects the environment often has on the temperature readings. If I sit in my car too long, the sun elevates my surface temp to 108 F. Not likely my internal temp… And if I’m in the cold too long, my surface temp got down to 93.4 F. Also not likely my internal temp…. because in either case, I’d be dead. The laser just doesn’t penetrate far enough into the person to reach those structures. So, common sense says it’s not likely. In addition to common sense, a literature search reveals no articles supporting the theory that the thermometer can penetrate deeper than the skin, especially not to the pineal gland. A pulse oximeter also uses red laser light, and we’ve been using those for how long now? No damage to speak of in fingers, ears, toes, torsos, or any other body region they are applied to.


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