No, the title isn’t a weather prediction, it’s about this study on human body temperatures in the US. It turns out that the truism that the average human body temperature is 37°C is less and less true over time: this study found that even taking into account that body temperatures have always varied around that point on an individual level, overall, the average body temperature is going down. In the UK, the average body temperature (according to the average over 35,000 patients whose temperatures were taken with an oral thermometer) is now 36.6°C.
That’s sort of an interesting fact, of course, but it would be more interesting to know why it’s happening. The authors theorise that it is due to the lower levels of inflammation that a person can expect to have now compared to the historical measurements. If people were always fighting off infections on some level, maybe their body temperatures were higher due to the immune response. They suggest chronic infections of syphilis, tuberculosis, malaria and periodontitis were possibly common enough, along with other infections, to produce an overall rise in the average.
I’m personally not sure that explains the decade-on-decade change they have also observed. Apparently, not only are our body temperatures lower on average, but that’s a trend which is continuing. It’s not clear to me that medicine is changing fast enough now for that to still be the case, and I would expect to have seen a large change at the time antibiotics were introduced. I’m not seeing that trend in their data.
Still, overall changes in inflammation due to changed hygiene habits and lower levels of physical work I could buy — and the observation is interesting in itself.