Normal human body temperature can be anywhere from a low of 94.5°F for an armpit reading of a baby age 0-2, up to 100.6°F for a rectal reading of an adult age 11-65. A fever can be as low as 97.5°F for an armpit reading of an adult, which is 1.1 degrees below the usually defined normal of 98.6°F, and a chill can be as high as 98.6°F for a rectal reading of an adult. There are numerous sites that a Google search finds that give these same figures, but there isn’t a large study source for them. These numbers are arbitrary, which seems strange considering there are 7.3 billion people and bodily temperature is a standard measure of health, and it would seem there would be an abundance of data.

The normal ranges for human oral temperature are for ages,

3—10 years  =  97.7°F  (95.9 — 99.5)  
11—65 years = 98.6°F  (97.6 — 99.6)
65+ years      = 97.4°F  (96.4 — 98.5)

Remember 98.6°F for adults and one degree less for young and old.

Here is a list of some factors that affect the body temperature

  1. Age of over 65 can lower temp a degree from a normal adult readings
  2. Vigorous exercise can add a degree or even two, for an hour
  3. Sleep deprivation
  4. Stress, fear and anxiety can raise and lower temperature unpredictably
  5. The threat reaction of fight, flight raises temperature and freeze chills it.
  6. Elevated blood pressure will raise it
  7. Non-sweating people will raise temperature during exercise
  8. A woman’s late-mid-month menses can add a degree, for a week
  9. Air temperature can raise or lower bodily temperature and that plus
  10. Humidity when combined with air temperature can add more change
  11. A hot bath within the previous two hours can add several degrees
  12. Clothing has an influence on bodily temperature depending on situation
  13. Being in direct sunshine, can heat up the body
  14. Being in a room with cold walls can lower the bodily temperature
  15. Time of day – late afternoon adds a degree – early morning minus a degree
  16. Body Mass Index over 30 will add to core temperature and reduce skin temperature
  17. Drinking cold water will drop oral temperature for a several minutes
  18. Drinking hot beverage will raise the oral temperature for a few minutes
  19. Spicy foods will flush the face and raise the oral temperature for a several minutes
  20. Some drugs will raise bodily temperature for hours, and some will lower it
  21. And finally, infectious disease and physical injury will usually raise bodily temperature

I just made up that list, from personal experience, of the many factors affecting human body temperature, but there must be many more. Also, some of these factors can probably be combined to vary the temperature several degrees either up or down.

What can be done to find your normal personal body temperature?

Right now while you are thinking about this problem get your oral thermometer and take your temperature, write down the exact time and circumstance, and do this for 24 hours. Do this whenever you are sick, or doing any of the activities listed above. My temperature, right now, at 6:30 PM is 97.8°F, which is right on average for an 80-year-old sitting at a computer for an hour. 10:00 PM = 98.0°F; 11 PM = 97.9°F. Those temperatures are a half a degree higher than what is usual for me; but I didn’t sleep well last night, so perhaps that raised my temperature.