I obviously only saw small parts of France on my trip, but a lot of the infrastructure, as you might imagine, is friggin' OLD. It's entirely possible that putting AC into many facilities is just too difficult in terms of interior power lines, ventilation, or other issues. It's hard to install central AC when your heat comes out of a radiator on the wall.

Of course, I saw the "tourist" part of Paris, where everything HAS to stay old. From the top of the Arc de Triumph, one could look in the distance and see New Paris, with skyscrapers of glass and steel. Probably also slidewalks, flying cars, and frequent spaceship launches. And I would bet, a lot of air conditioning.

Out in the smaller towns, I felt damn lucky the toilet flushed, never mind AC.