The question should be whether AC would be used much, but whether it has a net benefit. And yes, the environmental impact should be taken into account.
To me, that depends (a.o.) on whether those 1,500 excess deaths get ‘compensated’ by lower death rates just after the heat wave (which would mean many of those who died lost ‘only’ a few weeks)
Perhaps laws requiring community centers also function as temperature extreme shelters could be instated.
The laws would have to also provide funding to install and maintain AC and Heating systems suitable for the population around that area.
Additionally, if a business doesn't have AC or heating during extreme temperature alerts, it should close for the safety of the workers.
A more reasonable shortish term solution is to air condition large communal buildings and allow people to camp out overnight when the temperatures become inhospitable.
I think the most dystopian idea would be Exxon not paying for their crimes against humanity, but rather allowed to continue lying to the public about climate change, lobbying governments to reduce their penalties.
If that one week a year can kill people, still think it doesn't make sense?
Also the environmental impact of everyone having an AC, that's not good.
In France and the UK hardly any has an AC because it's not really needed. Your suggestion is that they spend billions of dollars for this? Who buys everyone the AC?
I lived in PNG which is near the equator and hot. It's not the temperature that's the true problem, but humidity. We stayed cool by using the fan, resting, removing clothing, swimming.