# 98.6 **URL:** \ **Category:** Factual Questions\ **Created:** [April 2, 2009, 9:00am UTC](https://boards.straightdope.com/t/98-6/491695 "2009-04-02T09:00:36Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![ManInTheJar](https://avatars.discourse-cdn.com/v4/letter/m/ea5d25/32.png) [@ManInTheJar](https://boards.straightdope.com/u/ManInTheJar)\ **Post date:** [April 2, 2009, 9:00am UTC](https://boards.straightdope.com/t/98-6/491695/1 "2009-04-02T09:00:36Z")
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? ---
**Author:** ![friedo](https://avatars.discourse-cdn.com/v4/letter/f/8edcca/32.png) [@friedo](https://boards.straightdope.com/u/friedo)\ **Post date:** [April 2, 2009, 9:16am UTC](https://boards.straightdope.com/t/98-6/491695/2 "2009-04-02T09:16:47Z")
98.6 is average. Many people vary by a couple degrees warmer or cooler. ---
**Author:** ![Derleth](https://avatars.discourse-cdn.com/v4/letter/d/b9e5f3/32.png) [@Derleth](https://boards.straightdope.com/u/Derleth)\ **Post date:** [April 2, 2009, 10:35am UTC](https://boards.straightdope.com/t/98-6/491695/3 "2009-04-02T10:35:03Z")
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). ---
**Author:** ![CookingWithGas](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cookingwithgas/32/485_2.png) [@CookingWithGas](https://boards.straightdope.com/u/CookingWithGas)\ **Post date:** [April 2, 2009, 1:22pm UTC](https://boards.straightdope.com/t/98-6/491695/4 "2009-04-02T13:22:56Z")
> [@Derleth](#): > > 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. Interesting claim, since the [Fahrenheit](http://en.wikipedia.org/wiki/Fahrenheit)scale predates the [Celsius](http://www.bartleby.com/64/C004/016.html)scale. 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. ---
**Author:** ![Wendell\_Wagner](https://avatars.discourse-cdn.com/v4/letter/w/8491ac/32.png) [@Wendell\_Wagner](https://boards.straightdope.com/u/Wendell_Wagner)\ **Post date:** [April 2, 2009, 1:37pm UTC](https://boards.straightdope.com/t/98-6/491695/5 "2009-04-02T13:37:27Z")
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: > **[Human body temperature](https://en.wikipedia.org/wiki/Normal_body_temperature)** > > Normal human body-temperature (normothermia, euthermia) is the typical temperature range found in humans. The normal human body temperature range is typically stated as 36.5–37.5 °C (97.7–99.5 °F). > Human body temperature varies. It depends on sex, age, time of day, exertion level, health status (such as illness and menstruation), what part of the body the measurement is taken at, state of consciousness (waking, sleeping, sedated), and emotions. Body temperature is kept in the normal range by a h... 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). ---
**Author:** ![bordelond](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bordelond/32/150_2.png) [@bordelond](https://boards.straightdope.com/u/bordelond)\ **Post date:** [April 2, 2009, 2:31pm UTC](https://boards.straightdope.com/t/98-6/491695/6 "2009-04-02T14:31:24Z")
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? ---
**Author:** ![Ludovic](https://avatars.discourse-cdn.com/v4/letter/l/7ab992/32.png) [@Ludovic](https://boards.straightdope.com/u/Ludovic)\ **Post date:** [April 2, 2009, 2:54pm UTC](https://boards.straightdope.com/t/98-6/491695/7 "2009-04-02T14:54:49Z")
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 🙂 ---
**Author:** ![SeanArenas](https://avatars.discourse-cdn.com/v4/letter/s/df705f/32.png) [@SeanArenas](https://boards.straightdope.com/u/SeanArenas)\ **Post date:** [April 2, 2009, 3:10pm UTC](https://boards.straightdope.com/t/98-6/491695/8 "2009-04-02T15:10:10Z")
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. ---
**Author:** ![EmAnJ](https://avatars.discourse-cdn.com/v4/letter/e/d2c977/32.png) [@EmAnJ](https://boards.straightdope.com/u/EmAnJ)\ **Post date:** [April 2, 2009, 3:15pm UTC](https://boards.straightdope.com/t/98-6/491695/9 "2009-04-02T15:15:48Z")
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. ---
**Author:** ![gigi](https://avatars.discourse-cdn.com/v4/letter/g/a587f6/32.png) [@gigi](https://boards.straightdope.com/u/gigi)\ **Post date:** [April 2, 2009, 3:32pm UTC](https://boards.straightdope.com/t/98-6/491695/10 "2009-04-02T15:32:19Z")
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? ---
**Author:** ![Bluffcityguy](https://avatars.discourse-cdn.com/v4/letter/b/ebca7d/32.png) [@Bluffcityguy](https://boards.straightdope.com/u/Bluffcityguy)\ **Post date:** [April 2, 2009, 3:50pm UTC](https://boards.straightdope.com/t/98-6/491695/11 "2009-04-02T15:50:09Z")
> [@bordelond](#): > > 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? From: [Fever - Wikipedia](http://en.wikipedia.org/wiki/Fever#Measurement_and_normal_variation) > [@](#): > > When a patient has or is suspected of having a fever, that person’s body temperature is measured using a thermometer. > > At a first glance, fever is present if: > > [ul]Temperature in the anus (rectum/rectal) or in the ear (otic) is at or over 38.0 °C (100.4 °F) [/ul] > [ul]Temperature in the mouth (oral) is at or over 37.5 °C (99.5 °F) [/ul] > [ul]Temperature under the arm (axillary) is at or over 37.2 °C (99.0 °F) [/ul] > The common oral measurement of normal human body temperature is 36.8±0.7 °C (98.2±1.3 °F). This means that any oral temperature between 36.1 and 37.5 °C (96.9 and 99.5 °F) is likely to be normal. > > However, there are many variations in normal body temperature, and this needs to be considered when measuring for fever. The values given are for an otherwise healthy, non-fasting adult, dressed comfortably, indoors, in a room that is kept at a normal room temperature (22.7 to 24.4 °C or 73 to 76 °F), during the morning, but not shortly after arising from sleep. Furthermore, for oral temperatures, the subject must not have eaten, drunk, or smoked anything in at least the previous fifteen to twenty minutes. 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 ---
**Author:** ![howye](https://avatars.discourse-cdn.com/v4/letter/h/a9adbd/32.png) [@howye](https://boards.straightdope.com/u/howye)\ **Post date:** [April 2, 2009, 4:10pm UTC](https://boards.straightdope.com/t/98-6/491695/12 "2009-04-02T16:10:17Z")
As an interesting data point, my wife’s “normal” temp. is 96.8. It makes temperature control in our house fun. ---
**Author:** ![FalconFinder](https://avatars.discourse-cdn.com/v4/letter/f/51bf81/32.png) [@FalconFinder](https://boards.straightdope.com/u/FalconFinder)\ **Post date:** [April 2, 2009, 5:29pm UTC](https://boards.straightdope.com/t/98-6/491695/13 "2009-04-02T17:29:36Z")
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. ---
**Author:** ![jujuju](https://avatars.discourse-cdn.com/v4/letter/j/7993a0/32.png) [@jujuju](https://boards.straightdope.com/u/jujuju)\ **Post date:** [April 2, 2009, 5:42pm UTC](https://boards.straightdope.com/t/98-6/491695/14 "2009-04-02T17:42:56Z")
> [@EmAnJ](#): > > 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. 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. ---
**Author:** ![flex727](https://avatars.discourse-cdn.com/v4/letter/f/258eb7/32.png) [@flex727](https://boards.straightdope.com/u/flex727)\ **Post date:** [April 2, 2009, 6:20pm UTC](https://boards.straightdope.com/t/98-6/491695/15 "2009-04-02T18:20:14Z")
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. ---
**Author:** ![EmAnJ](https://avatars.discourse-cdn.com/v4/letter/e/d2c977/32.png) [@EmAnJ](https://boards.straightdope.com/u/EmAnJ)\ **Post date:** [April 2, 2009, 7:15pm UTC](https://boards.straightdope.com/t/98-6/491695/16 "2009-04-02T19:15:32Z")
> [@jujuju](#): > > 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. 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. ---
**Author:** ![Labrador\_Deceiver](https://avatars.discourse-cdn.com/v4/letter/l/7c8e57/32.png) [@Labrador\_Deceiver](https://boards.straightdope.com/u/Labrador_Deceiver)\ **Post date:** [April 2, 2009, 7:24pm UTC](https://boards.straightdope.com/t/98-6/491695/17 "2009-04-02T19:24:23Z")
> [@EmAnJ](#): > > 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? ---
**Author:** ![Projammer](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/projammer/32/559_2.png) [@Projammer](https://boards.straightdope.com/u/Projammer)\ **Post date:** [April 2, 2009, 7:25pm UTC](https://boards.straightdope.com/t/98-6/491695/18 "2009-04-02T19:25:23Z")
The master has somewhat [addressed](http://www.straightdope.com/columns/read/845/on-the-fahrenheit-scale-why-is-32-freezing-and-212-boiling) this. ---
**Author:** ![Kuboydal](https://avatars.discourse-cdn.com/v4/letter/k/ecb155/32.png) [@Kuboydal](https://boards.straightdope.com/u/Kuboydal)\ **Post date:** [April 2, 2009, 8:32pm UTC](https://boards.straightdope.com/t/98-6/491695/19 "2009-04-02T20:32:49Z")
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. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [April 2, 2009, 8:38pm UTC](https://boards.straightdope.com/t/98-6/491695/20 "2009-04-02T20:38:44Z")
> [@](#): > > I’m guessing you have your reasons, but aren’t the little sticks easier & more accurate? 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). [Next page](https://boards.straightdope.com/t/98-6/491695.md?page=2)