I had to look up "autoclave". Are you connected with medicine? Your confidence makes me think so. I am not connected with medicine in any way.
I beg to disagree with your assertion that
you need sensible physical model of the physical process
I feel that this "need" is perhaps defining of modern medicine, or what is lacking in "traditional" (quack?) medicine. But upon considerable reflection, as far as I am concerned, if a treatment works I do not, or at least I feel I should not, care if it has or has not a model for how it works. When I think carefully, I really do not care at all, so it strikes me as kind of strange that this "need" be felt to be so widespread, even in myself.
[For example, I imagined people with their feet in hot water and ice packs on their head, and thought "*how* could that work!?" and because I did not have an answer to the how question, I rejected the suggestion, putting it out of my mind completely. It was only when I thought of a preliminary answer to the how question that I allowed myself to consider the evidence for effectiveness. Wherefore this need to explain? Can we ditch it? Would it be unwise to take the attitude that, *if* it works, then it works? ]
I can now think of ways in which fever, thermotherapy, and localized cooling might be helpful in combating disease. I am not connected with medicine so I am not sure it helps to mention such models, but I will.
HOW?
0) First of all the WHO claim that baths do not have (significant) affect upon body temperature due to the homeostatic regulation of body temperature. Typical fevers are in the range you mention, and research shows that hot baths have only a very small effect (E.g. 0.5 - 0.7 Celsius).
1) As you point out, and is pointed out by the WHO (the seem to use the same reasoning as you) the human body can not reach the 'autoclave' temperatures required to kill human viruses. Hot baths, and fevers increase body temperatures by a relatively small amount. However as pointed out by more than one of the papers that I link from my photo above, it is argued to be the case that there is a far narrower window of
at least climatic temperatures are required for the virus to human infect cells. If the virus cannot infect, then it can not replicate. There are presumably ways in which there is an attrition in the number of pathogens ingested (?) over time. So heat would only need to reduce infectivity and not result in viral death to produce an ameliorative effect (if not a "cure").
www.biorxiv.org/content/10.1101/2020.02.17.952903v1
"With the rising (climatic) temperature, 2019-nCoV is expected to decrease
its infection ability much faster than SARS-CoV, and get
controlled more easily"
2) Localized cooling especially of the head is something that old men in Japanese baths use to help them to stay in hot baths for longer. It is clear to me that hot baths and fever can be dangerous, and are also subjectively unpleasant. If cooling the head helps overcome the latter unpleasantness AND if there is a mechanism by which heat reduces viral infection (1) then localized cooling, e.g. by keeping patients in beds or foot baths outside, and palliative measures of this kind, may at least increase the time before the patients and their care givers reach for the anti-pyretic medicine (aspirin in 1918, ibuprofen until recently, and paracetamol as recommended even now).
But as I say above, I am not connected with medicine, and would rather forget the hows and models.
Reading about thermotherapy and how fever effects outcomes on google scholar, I find myself persuaded that even if the how explanation, the model above is incorrect, there is evidence, or at least conjecture on the part of medics, that higher body temperatures do sometimes result in more positive outcomes.
This (old) paper on Fever, divides medicine into the empirical (where it was only important an effect was found) era and scientific era (where models became important)
www.ncbi.nlm.nih.gov
This paper argues against the notion that fever is an epiphenomenon
Fever is a very common complaint in children and is the single most common non-trauma-related reason for a visit to the emergency department. Parents are concerned about fever and it’s potential complications. The biological value of fever (i.e., ...
www.ncbi.nlm.nih.gov
The paper on bats suggests that "flight as fever" may have advantages
Bats are sources of high viral diversity and high-profile zoonotic viruses worldwide. Although apparently not pathogenic in their reservoir hosts, some viruses from bats severely affect other mammals, including humans. Examples include severe acute respiratory ...
www.ncbi.nlm.nih.gov
I am not connected with medicine.