How is it that we humans all seem to have our internal thermostats set at the same temperature 98.6 F / 37 C? Do some people have "normal " temperatures significantly higher or lower than that?
98.6 is average. Many people vary by a couple degrees warmer or cooler.
In fact, 98.6°F is too precise: It’s the result of someone converting 37°C to Fahrenheit and not realizing that the Celsius temperature only had two significant figures. It would likely be more realistic to say normal human body temperature hovers somewhere around 99°F, with differences throughout the day as dictated by activity level and circadian rhythm (the wake-sleep cycle, which generally makes people cool down when they’re entering their normal sleep phase).
Interesting claim, since the Fahrenheitscale predates the Celsiusscale. Also, even if it is from a conversion, how do know that the conversion isn’t from 37.0°C, with three significant digits?
However, I have seen conflicting accounts of how we got to 98.6, so I’m not sure we can make a definite statement at all.
It was first calculated in 1861 by someone who used the centigrade scale. The figure he gave was 37 C. This was converted in Fahrenheit to 98.6 F. Here’s the Wikipedia article:
As you can see, a modern estimate is 98.2 F plus or minus 1.3 (or equivalently, 36.8 C plus or minus 0.7).
How far off of the average can a healthy person’s body temperature be?
Are there any cases in the medical literature of a healthy patient coming in for something mundane, and then in the course of collecting routine vitals it turned out that this patients’s normal body temperature was, say, 101°F or something?
Mine’s exactly 98.6. I thought it trended a bit higher before I realized I was only measuring my temp when I had a fever 
At the doctor’s office, they always measure mine at 97.x. It was 98.1 once. When I have a fever it’s usually about 100.
I think it really varies depending on the person and time of day. I take my temperature every morning before I get out of bed. This morning it was 96.70, yesterday it was 97.3, two weeks from now it’ll likely be around 98.25 or so.
If your temperature is normally lower than average (say, 96), is it true that a fever for you is also lower, or does the dangerous temperature level stay the same?
From: Fever - Wikipedia
FWIW… IANADoctor but that sounds right to me, though on that oral figure (febrile if oral temp > 37.5C/99.5F, I’ve never known doctors (including that esteemed pediatric specialist, “Dr. Mom”) to get terribly worried if the temp wasn’t over 100F/whatever C (too lazy to convert now).
Cheers,
bcg
As an interesting data point, my wife’s “normal” temp. is 96.8. It makes temperature control in our house fun.
Mine used to be a consistent 98.6. Then, several years ago (I forget how many, now) I had a long-term (6 weeks to 2 months or so) low-grade fever. The Doctor called it “fever of unknown origin” and nothing was able to be done about it. It went away on its own, but I never felt quite right afterward…
Then, due to an increasing number of symptoms, it was found that I’m Hypothyroid. Now my temps are in the low 97 range.
I know I have a fever (because of the way I feel) when I hit 99 or so.
I have to ask, why do you take your temp every morning before you get out of bed?
My normal temperature, when taken at the doctor’s office, is 97.8°. If it is above 99°, I feel like I have a fever.
My normal body temperature is over 99 F. When I was a child, I could get out of school anytime I wanted by requesting a trip to the nurse, who would take my temp and proclaim that, though it wasn’t much of a fever, it was above normal and send me home. I didn’t take advantage because my mother knew better.
I’m trying to get pregnant, so I take my temperature daily (must do it before I get out of bed) to track my cycle and ovulation.
I’m guessing you have your reasons, but aren’t the little sticks easier & more accurate?
The master has somewhat addressed this.
I discovered that my temperature was generally 99.1F when I was a kid. This made it rather easy for me to stay home and read in bed rather go to school whenever I chose to do so.
The little sticks tell you if you are pregnant, not if you’re likely to become pregnant. A woman can tell when she’s ovulating based on temperature and assorted other factors (some of which are probably TMI for this thread).