the body maintains stasis in many areas, some more critical than others and each with an optimal range and individual exceptions(or exceptional individuals, if you prefer). the pH of the blood doesnt have much wiggle room while core body tempuature and blood pressure and degree of hydration can vary immensely and still be within range for a particular activity or environmental pressure.
i figured out early on that normal body temp is a very relative thing. i also believe that we should all be higher temp. i think 100 is normal, which explains the medicos apprehension at anyone who has what they call a low grade fever. fever reducers are life reducers, pure and simple. the fear came from instances of dying with high temps. people dont die right away with low temps. they simply sit around in a living hell and slowly die while listening to people deny they even have a problem. thats when i got busy and fixed it my own self.