I keep my two prehensile slinkies in my bedroom, and I've noticed with the weather becoming frigid, my room does not get as warm as the rest of our 3 bedroom apartment. I think it has something to do with my room being on the other side of the hall as the closet that contains our HVAC unit. My room stays 15 to 20 degrees colder than the communal spaces or the other bedrooms. As annoying as it is to sleep in there, I am more concerned about my animals not having proper ambients.

I'm considering putting up curtains to prevent a draft from the windows, which I'm hoping will help exponentially. In the event it doesn't, does anyone have any ideas that DON'T involve a space heater? I am reluctant to leave one running all day without supervision, and I already have a mini fridge running in my room for rats, so I'd prefer to avoid using even more energy.

Their hotspots maintain the proper temps, but their ambients and cold side are too low for my comfort. Any suggestions would be helpful.