Acute heat exposure, like 45 minutes where sweat is starting to accumulate on your skin, causes capillary growth and other adaptations some weeks later. If you don't have those adaptations already when exposed to heat, and you're weak, you're going to be in trouble.
I guess this explains how I could play tennis for two hours in the sun in 35 degree heat (35 C in shade). I guess I'd better not try it again now that I haven't done it for a while.
It seems like they use obscure language (non-optimal, excess) on purpose to try to somehow connect global warming into the obvious fact that a lot of people die in cold temperatures if they don't have a warm shelter, and sometimes people die in hot temperatures if they don't drink enough. And the article is full of global warming fear mongering, although they found that temp-related mortality has decreased from 2000 to 2019.
That's probably still very healthy. The study looks at deaths per year at non-optimal temperatures. Living in a desert is different than taking a sauna.
"Sub-Saharan Africa had the highest cold-related excess death rate"
That's an interesting choice. It conflates cold-related excess deaths in the equatorial lowlands (which struggle to ever get below 70F/20C) and the southern highlands (like Lesotho, which routinely goes below freezing in June/July). Both are sub-saharan.
Of course, that may just be a bad summary, but it puts it onto the "should probably verify the results before I trust it" pile of papers, something that's sadly growing at an ever-increasing pace.
That's an interesting choice. It conflates cold-related excess deaths in the equatorial lowlands (which struggle to ever get below 70F/20C) and the southern highlands (like Lesotho, which routinely goes below freezing in June/July). Both are sub-saharan.
Of course, that may just be a bad summary, but it puts it onto the "should probably verify the results before I trust it" pile of papers, something that's sadly growing at an ever-increasing pace.