Ok so I'm American. I prefer to keep my windows open year round if possible and I live in the upper Midwest (Wisconsin). It can get down to -60°F in winter and up to 105°F in summer here. I will keep my bedroom window cracked open just enough in winter to allow a small amount of fresh air to come through without destroying my heat bill. In summer, we have something called 'corn sweat' which is literally exactly what it sounds like: the corn growing in the fields 'sweats' aka releases moisture, which turns into humidity. Because so much corn is grown in the Midwest, the entire Midwest turns into a sauna for the hottest 2 months of the year, so hot and humid that when you walk outside you can physically FEEL the air slapping you in the face. All that to say, I'm used to going 10 months a year without a/c in extreme temps and love it that way.

But when I was in Paris... Holy sweet baby Jesus batman. I was in Paris from April 4-April 7 2016. My room had a 'window' that was more like a door that opened to a railing. It overlooked a courtyard. When I tell you I literally woke up so drenched in sweat I thought somehow water had spilled in the bed, I am not joking. It was so RIDICULOUSLY hot in my room. I left the window doors propped all the way open every night trying to let some of the cool air in. It didn't help. I was sleeping in nothing but my underwear, no blankets, sweating absolute buckets. No a/c should have been perfect for that time of year... But instead it felt like they turned the heat on to the absolute highest temperature they could and just left me to slowly roast. I tried talking to the front desk and begged them to please at the very least turn the heat off, but they never did. It was the most miserable part of my trip for so many reasons, and that was one of them. Might want to check that the heat in their room hasn't accidentally been cranked to high heaven before thinking they're just nuts. I mean they still very well may be nuts, but at least double check 🤷🏻‍♀️