I can’t imagine flying without AC for many minutes but I guess they used to do it long ago when planes were in the air before the invention of a/c.
It must have been 100F in the planes, especially when they had a bunch of people in the plane.
I’m on a many minute flight to Europe right now and feeling pretty comfortable with a bunch of legroom in row number one. The only bad section is that there is no space for my backpack or PC. The wonderful section is that I have a freezing a/c vent right in front of me keeping me nice and cool. I guess next time I fly overseas I am going to treat myself to a first class seat. I guess it costs a lot more however it would be worth it one time. I asked the stewardess if they had a HEPA filter in the Heating, Ventilation as well as A/C program and she said she wasn’t sure. I would hope they have them in this day and age with COVID. I almost lost my suitcase when I went to the bathroom and left it in there. I went back however couldn’t find it, however luckily I found security and they had it. That was frightening as my ipad was in it with all of my Heating, Ventilation as well as A/C work and writing that I did offline for the past week. I would have lost the work, and more pressingly, the ipad that has my whole life on it. I better back up my Heating, Ventilation as well as A/C industry writings and all the info on the PC.