Montréal is an island and therefore rather dense, so almost all of its milongas are in built-up areas. The city insists that the windows stay shut while music is playing, as that moderates the noise level – when grumpy neighbors complain, the city sides with them. Consequently, we have hot, humid milongas with minimal air circulation even in winter, when it's -30°C outside with a dry wind that makes it feel even colder.
(Part of me wishes that our milongas were like '80s and '90s raves: Out in the industrial wasteland far from residences and businesses, in warehouses with half the windows broken. The music and air circulation could both be strong at the same time!)
This doesn't matter for me right now . . . I tested positive for COVID-19 on November 3 and still test positive today, November 15. Our region is pondering a return to height-of-pandemic restrictions – not for COVID-19, but because of severe influenza and RSV outbreaks among youngsters – so even if I were the sort who'd dance with a positive test, which I'm not, this wouldn't be the time to do it. The social and legal ramifications would be too severe.
Once I test negative and can return to the milonga, I'm going to be searching for the very few that leave the windows open. I find it far easier to deal with a 10°C room with breeze than a 35°C room with still humidity.