It feels so weird to me that the small change in degrees might actually kill a virus. I mean, wouldn’t all viruses by now have become accustomed to “warmer climates”?
Or is it a cat / mouse game, our bodies being able to heat up more and them getting more fire resistant by the year. Was a fever less hot a couple of hundred years ago?
I am not an expert but I believe the temp threshold is for when proteins denature due to the ambient heat overcoming the strength of the bonds (mostly h-bonding i believe) that hold the protein in its specific tertiary structure and when you exceed it the proteins unfold/break
I read that this is a common misconception: the high heat is not enough to denature any proteins (else it would kill you too) and, what’s more surprising, it actually makes viruses/bacteria more active. But it also makes your immune system more active, with an overall win in effectiveness over the microbes, which is what makes it useful.
It’s in the air if viruses are even alive, you’re giving them way too much agency in the matter.
Viruses do adapt and mutate though. Look at all the various strains of H1N1 and SARS-COV-2.
Just because they don’t reproduce without a host cell doesn’t mean evolution doesn’t happen. If a trait emerges that is beneficial to future generations, viruses carrying that trait can infect more cells and spread further.
Usually it’s evolution itself that people give too much agency to. Mutations are a crapshoot. They can be beneficial or they can cause birth defects, sterility, prevent reaching sexual maturity, or make finding a mate excessively difficult. Or all of the above.
Heat resistance generally reduces a pathogens fitness at normal temps. The human body is also far more heat resistant than individual viruses thanks to being a big multi cellar organism with many expendable cells. A fever isn’t your only method of dealing with viruses either, you’re just stacking the deck against them do your immune system has a better time.
