Armpit Vs Oral Vs Rectal Temperature And "optimal" Range

[Mufasa]

I'm a bit confused if people talk about temperatures. I thought that different methods for measuring temp would give approximately the same readings, but they seem quite different, at least in my case.

For example, in the late afternoon today, I had those readings:

- Armpit: 36.8 C (98,24 F)
- Oral: 37.1 C (98,78 F)
- Rectal: 37.5 C (99,5 F)

Now I read, that after lunch, 98.6 F would be a good temperature. But do they mean the armpit, oral or rectal temperature?

 

[Parsifal]

When you say oral, is it under the tongue?

 

[Mufasa]

When you say oral, is it under the tongue?

Yes

 

[Mufasa]

I was measuring some more today.

Oral temperature seems really not trustable to me. For example, right after a meal it was 35.5 degrees, but only 30 min. later it was 36.8.
I also don't really trust armpit temperature, because my left arm is around 0.3 degrees lower than my right arm...

Rectally, I get readings that seems more trustworthy to me. Yesterday it was 36.5 when I wake up, quite quickly after breakfast it raises to around 37.2, peaking in the afternoon around 37.6, and before I go to bed it is around 37.1.

 

[whodathunkit]

Oral temp is affected by whatever you put in your mouth. So if you have cool drink or any food you should wait 30 or so minutes to ensure you're getting your actual temp, not a temp with some of your body heat dissipated into the cool liquid or the food you just swallowed.

For axillary temp: do you leave your thermometer in your armpit for a few minutes before taking the reading? IME it's necessary to do this even with digital thermometers. Your body heat dissipates every time you lift your arm so when you take a true axillary temp you should let any thermometer warm up a bit before getting a reading. Letting it warm up is the only way you're going to get a reasonably true bead on what your temps are like at your extremities.

Rectally, I get readings that seems more trustworthy to me. Yesterday it was 36.5 when I wake up, quite quickly after breakfast it raises to around 37.2, peaking in the afternoon around 37.6, and before I go to bed it is around 37.1.

I don't know what the consensus is around here but my understanding is that axillary temp is the best indicator of how well our body can keep our extremities warm, which is really what we're concerned with. Warm extremities mean a high metabolism. When under stress the body will conserve heat "inside" the body to protect internal organs and vital processes. After all, we can live without a finger or even a whole hand, but not without a heart. Oral and rectal are both more equivalent to internal temp that is always going to be highest, axillary more equivalent to extremities.

Again, just my understanding. Hopefully others will chime in who know more.

At any rate...is it really feasible or even desirable to take a rectal temp several times a day?

 

[Blossom]

Rectally, I get readings that seems more trustworthy to me. Yesterday it was 36.5 when I wake up, quite quickly after breakfast it raises to around 37.2, peaking in the afternoon around 37.6, and before I go to bed it is around 37.1.

I find rectal to be the most reliable too although it can be inconvenient.
Forum member @Mittir mentioned an ear reading as being a good option but you'd have to buy a specific thermometer to check it that way.
Where To Measure Your Temp, Best Type Of Thermometer?

 

[Ahanu]

But do they mean the armpit, oral or rectal temperature?

Armpit. Broda Barnes used the armpit. Rectal temperature is higher. About 0,5.+-

 

[Jsaute21]

Armpit. Broda Barnes used the armpit. Rectal temperature is higher. About 0,5.+-

Isn't armpit a degree lower typically?

 

[GreekDemiGod]

I also don't really trust armpit temperature, because my left arm is around 0.3 degrees lower than my right arm...

This is exactly what I realized. My left armpit registers lower than my right armpit.