We travel a lot of budget and we know what standards we can expect. No fuss, just a clean room with a bed, tv, shower and toilet. And some air... normally.
Not many budget hotels in Europe have AC (contrary to the US) which is sometimes a shame. But opening a window also helps.
On our visit to Ibis Budget the interior of the hotel and the rooms was immensly hot and moist. Try, there had been quite some rain in the weeks prior to our visit and it is summer, but this was all but comfortable. Our room was situated on the first floor (second floor for some) at the back of the hotel. There was a giant wall of bushes right up against the hotel creating a crawling nest of mosquitos.
So before we went to sleep, we had to hunt down literally dozens of mosquitos in our room and we couldn't open up the room. Since the lack of air/oxygen was simply intolerable I decided to go and ask for another room. A room on the ground floor was for some reason not possible nor was a room at the front of the building, away from the mosquito bushes... And judging by the parking lot and the people seen moving about the hotel, there were not that many guests staying there.
I do understand that weather conditions cannot be influenced by hotel management, but looking for solutions is. I understand that AC isn't standard (yet) in European budget hotels but having sifts before the windows could be a major help as well.