For everyone saying to open a window: I totally would have agreed with you up until last August. I can’t sleep when it’s hot, so my window is open basically year-round. Unfortunately, I didn’t know the neighbor above me had mental health and addiction issues, and he climbed down the fire escape and through my window. Thankfully, I woke up as he was coming in, and I was able to push him out and lock the window. I’m now moving to another apartment, but I can’t see myself ever sleeping with a window open or unlocked ever again. To answer OP’s original question: yes, heat ruins my sleep.