Hello all! 
I’m pretty new to camping and have only been a few times. I feel the cold at night, even with hot water bottles, thermals etc. I don’t go electric hook up camping so I was looking at getting a little gas heater to use briefly in my tent to just take the edge off the cold.
I know they shouldn’t be used in unventilated spaces so was planning on opening my tent door and just running it at the other end of the tent for about 20 minutes. Would this be okay? I certainly don’t want to get CO poisoning but have heard running it briefly should be okay - advice from more seasoned campers welcomed!
Thank you!