I can’t even rely on body temp rules? And nobody told me?
Think of all the medical texts that have to be changed.
I have always looked skeptically at people who said–Oh, my temperature is different from most people’s.
The essay below shows that the research, now kinda old, showed an average temp of 98.2 not 98.6 in the population studied.
99.6 is the rectal temp, one degree Fahrenheit higher, skin is lower, under the tongue is supposed to be 98.6 F.
However your temp does vary with the circadian (hormonal) rhythms of the day.
Dogs run at 101-102 F. Horses less but they both run fevers when sick or overheated. So fever is the thing, normal temp may be as this report says–a little lower than we say it is.