I live in a latitude about the same as Spain, Southern Italy, Greece and Turkey, but in my part of the U.S., it's been above 30 degrees Centigrade for a few weeks, with high humidity. Our winters also get around 0 Centigrade (+- 8 or 9 degrees) pretty regularly, so we need to supply both heating and cooling.

Usually when it gets above 24/25 C we start to really put on the air conditioning. And below 20 C we put on the heat. A/C is generally important for not only cooling, but reducing humidity so your body's sweat actually does something useful.

I've lived in houses around here that didn't have A/C and it's pretty dreadful in the summer. You basically don't do anything during the day, and it's too hot to really sleep comfortably. Even fairly poor people usually end up with at least one room with A/C.

This isn't true for all of the U.S., the Pacific Northwest (e.g. Seattle) and Northern California tends to not have air conditioners because it doesn't usually get hot enough.

Quite a bit of the U.S. is at the same latitude as North Africa or the Middle East, the northern-most bits get maybe to Belgium? So even with the temperature gradients that ocean currents and global air movement affords, we get total sun that's more like areas of the world people associate with being "hot".

Having been to Europe numerous times, I notice most public areas, cars, buses, trains and offices seem to have A/C. So I'm sure you spend more time in it than you may realize.