Someone info-dumped on one of my favorite topics! About how generations are developing significantly cooler resting body temperatures (/lower metabolisms) and we don't actually know why. (I would love to look at this across the globe, too!)
@pamela op has got one fact flipped in their summary—cooler body temps are generally *more* hospitable to viral infections than warmer ones (this is why your body will give itself a fever when trying to kill viruses!) if we’re getting cooler bc of changing immune conditions it would mean our bodies were getting sick less often (eg sanitation has gone up dramatically) rather than our ability to treat going down (which is not necessarily true when you’re talking about a timescale that started during the American Civil War—well pre-penicillin let alone even dreaming of antivirals
anyway, text article on the same topic for anyone who does worse with audiovisual things: https://www.scientificamerican.com/article/are-human-body-temperatures-cooling-down/