LMAO, I don't know that I'd call freezing one's butt off a cultural experience or cultural difference. It's just the Landlord trying to keep his utility costs in check for as long as he can before the heating season gets into full swing. No idea whether an "official" date exists in France or Spain, but in every U.S. apartment I've ever lived in that included heat in the rent, said heat was never turned on before October 15th which, in some states I lived in, was the rule made by housing courts mandating landlords get the heat on by that date.
Now in every place we've lived where tenants are the ones responsible to pay for our own heat or air, it's never been an issue to flip back and forth from a/c to heat back to a/c again as our weather can be strangely fluid this time of year.
I don't know what part of the U.S. you are from, but people's tolerances for cold do run differently so October in parts of France and Spain could be very different than your seasonal "norm" back at home. I can always tell who the Canadians are in Cape Cod and Rhode Island because they are the only ones splashing in the ocean in early June when I won't even think about sticking my toe in the water until much later in the season because it can be hot on land but the ocean can remain cold.
Just think of this as a lesson learned for future travel in shoulder season (same goes for Spring travel) to be prepared with your packing. I love Land's End Thermaskin pants and their long sleeve crew neck - really soft, super lightweight and take up hardly any space in my bag (I go carry-on only). They keep me really warm and I can easily layer them under my pajamas if I need to or even my daytime clothes if it's suddenly really cold outside.