the problem is that the average body temperature is slowly decreasing, so this isn’t that well defined, we would need to link it to an event that is at constant temperature
also the celsius scale isn’t that good imo because it’s about the freezing and boiling of water at ambient pressure so it isn’t universal
I say we set the boltzmann constant to a known value, and define temperatures from there
after that we find a range of temperature with useful round values and offset the scale for everyday use
we found the main character of the universe