Secondarily, should the fan be outside or inside the window?
Asking for a friend. (Me, help. I can’t remember physics, it’s too goddamn hot)
Edit: I’ve opened all the windows and set up a fan a short distance from the window pointing out and it’s reduced the temperature to near-tolerable levels. Unfortunately, venting through the attic was a no-go but moving things aside might make it an option next time. Thank you all, I appreciate the help!
Happy to hear you solved it for now. For a more long-term solution, consider investing in an air conditioner. And make sure it also has a heating mode (a.k.a a heat pump), it should cost pretty much the same and is the most efficient way to heat a home in winter.