Ignoring for a moment the nativist undertone of your comment, it is not unheard of for people to hear the term-of-art for a concept they already understand and have to look it up.
It seems to me that once one realizes what a "wet bulb temperature of 35 C" means, it's only a hop, skip, and a jump to comprehend the immense vacuousness of your claim that billions of people will be regularly experiencing it.
> poor power infrastructure to run AC is bad
I agree. Let's not stand in the way of any developing nation building cheap, reliable power infrastructure along with cheap, reliable, flexible transportation infrastructure (aka roads and gas stations), so they too can travel in air-conditioned comfort from air-conditioned location to air-conditioned location.
Oh, yes, that means not destroying economic wealth.