Unfortunately my daughter is also stubborn and often doesn't understand what she's experiencing. And also tends to think her opinion matters more. So, I'm not saying it's easy if she's like that. I have to sort of suggest things calmly and walk away and let her think about it. Let her know how you guys feel. "Hey, we're actually really hot and uncomfortable and because of that I'm sweaty all the time (or whatever). Maybe you could get an electric blanket and some noise cancelling headphones or what do you think because this is really stressing us out. Do you have ideas? " And then don't make demands and wait to see if she bends a little. If not you need to talk to the landlord and make a complaint I fear.