To be fair...
As a tourist, I spent my time in what would probably be called the "old town" parts of places like Paris. If you walk up the Champs Elysees* to the Arc de Triomphe (which is as far as we went), a modern, futuristic skyscraper-filled Paris can be seen on the far side of the Seine, several miles further up the road, and a huge metal monument called the Arch de la Defense. I imagine they had glass-covered hotels which certainly had air-conditioning.
* We ate at the McDonalds there--it was the first McDonalds I ever saw that had fresh apple slices. All the U.S. ones do now. While remembering, I took a stroll past the place again on Google Earth, and spent some time looking around the new part of Paris.