Laith Al-Shawaf at Areo:
If you infect a rabbit with a virus or a bacterium, it’ll start to run a fever. Why? The surprising answer is that fever is not a disease; it’s a defence: a useful evolved mechanism that animals use to kill invading pathogens. Studies show that if you give fever-suppressing drugs to infected rabbits, they’re more likely to die.
It’s not just rabbits—all warm-blooded creatures use fever to kill invasive parasites. Animals that can’t regulate their body temperature internally take a different approach. For example, infected lizards seek a hot rock on which to sunbathe, raising their body temperature and killing the invaders that way—and research shows that disrupting their ability to do this increases their likelihood of death. Infected fish and reptiles exhibit this kind of “behavioural fever,” too. In humans, some studies find that administering fever-suppressing drugs to children may worsen outcomes and prolong the period of illness.
These findings suggest that fever is not a symptom of a disease; it’s an evolved defence that our bodies use to kill harmful invaders. Discoveries like this represent one small part of a larger picture emerging from the new science of evolutionary medicine. There’s a scientific revolution brewing, catalysed by the idea that considering how our bodies evolved will help us better understand and treat disease.
More here.