For the young and healthy staying cool is most commonly a matter of comfort. But AC, staying cool in general, can be a real survival issue for everyone some of the time, and serious business for some people all the time. For the elderly and those with heart and lung conditions inability to stay cool enough is serious business.

Temperatures in the 80s in Western Europe, where AC systems are uncommon, people are not acclimated to heat, and the public was not educated about the potential risk, had the old and infirm dropping like flies.

The US doesn't often do any better. This blunted only because we have a lot more AC systems and scattered old folks kicking off in an overheated houses seldom even makes the news. Unless we see a real 'heatwave' event and the morgues get backed up with bodies. In which case there may be some community effort to mitigate the effects.