As a government, it's probably a good move to encourage installation of AC in your citizens homes even if it only gets used a couple of days a year simply for the productivity benefits.
Unfortunately, current UK policies on Heat Pumps specifically discourage installation of AC (you become ineligible for various grants if your heat pump system has a valve to allow use as an AC system).
Many people forget that London (UK) has about the same latitude as Vancouver (Canada).
Different story for badly built apartments, though. We used to live in a 1950s apartment, top floor with a flat roof. It reached 38C inside, when outside was 36C, and then wouldn't cool down at all during the night. It was unbearable, and we moved out!
Not much help if you buy an existing place whose builders didn't take hot summers into account though!
And a fair chunk of that is the summer holiday season, when a lot of people won't be home anyway.
It is possible to mis-design houses and apartments to need it more than that (extreme sun traps essentially); schools/offices and public transport are a different case because of the number of human bodies in a small space.
But our homes need A/C so rarely that it's not worth it, same as most people don't have winter tyres or snow chains, or even know how to fit them. Materially significant amounts of snow for a few days one winter in three, unless you live in Scotland or the Pennines.