Today I learned Why the human body temperature is 37 degrees
We are the product of millions of years of selection and it’s likely we (mammals) have been through a phase of fungal selection.
“Fungal species that can thrive and infect an animal typically declines by 6 percent for every 1° C rise in temperature.” Increasing body temperature reduces the risk of fungal infection. However, there is an energy cost associated with maintaining that temperature.
It just so happens that “the optimal temperature for maximizing benefits while minimising costs was found to be 36.7° C, which closely approximates normal body temperature.”
If that temperature was 40 C, you may have had to eat twice as many calories daily to sustain your body temperature (I’m speculating and “twice” is arbitrary). So you can hate fungi for not giving you an excuse to eat six meals a day. Or you can thank fungi. Regardless, you are probably fungi selected.