Open door in winter. To charge?

Pretty much as the title reads.

Had a group check out yesterday and they left the front door open 12 inches. It’s winter here and was in the teens last night. House was also fairly dirty but our cleaner is a saint and only charged us an extra 30 dollars.

I typically don’t charge the guest for such low amounts but the open door thing has me a little frustrated. We heat with electric and it’s not cheap.