Kat,
I too am an "open window" person. This summer I have had three very messy young people living with me. The boys' room smells like a locker room. I refused to put in an air conditioner because it would close off any circulation. Now it's getting chilly at night. They run around closing windows. I run around opening them because I can't stand the smell of gym socks. Wait until the first snow!
In complete understanding,
Mary
Of course you could offer to cuddle up close and keep him warm. Just a thought.