It's winter time and getting colder, I was wondering if I can turn on my heater when my finches around near my living room? Not the one for the whole house, but portable ceramic heater we used to buy from the stores. I don't know if the heater will be toxic/ poison to them?

I wish can make them warm too by have heater on nearby, even their feathers should be warm enough. By the way, most of my finches live alone in a cage for now. Usually 2 better because can keep each other warm, but I need to find out which ones get along with other first, which not know until I move them around for next couple weeks a least. I just worried if can have heater on around my finches, I hope the answer is yes

if yes should I leave my bedroom door close when heater in my room? Any suggestions will be great! Thanks in advance!