I will be taking a trip this winter and staying in a rustic basically 1 room log cabin where the main source of heat is a fireplace. Just a stone hearth and chimney. I believe it doesn't even have a damper. My only experience has been with wood stoves.
I've seen it said numerous times that fireplace don't heat the interior they suck the warm air out. Obviously they must do something since for hundreds or thousands of years this was the main source of heat for many.
Considering I can't make any modifications to the structure, what can I do to increase comfort and conserve fuel? Is there any hope of walking up to a somewhat comfortable temperature without having to feed the fire in the middle of the night?