[irdc]

The widespread availability of air conditioning plus the fact that we've had such events before on rare occasions (see https://en.wikipedia.org/wiki/Wet-bulb_temperature#Highest_r...) and we didn't see bodies piled up in the street back then.

[RetroTechie]

True.. so far.

All that's needed is an intersection of high-humidity heat wave + densely populated area + extended power outage.

And/or too few buildings that have A/C or other places to escape the heat like swimming pools, metro tunnels or whatever.

Probably more likely to occur in less-developed areas like India or Africa. But regardless, could happen in many places. Just a few degrees might be the difference between 1000s or 100k+ deaths.