Chicks in January?

I was afraid this would happen.  The hen sitting on eggs on top of my haystack hatched her chicks today.  She somehow brought three chicks down from the top of a huge pile of bales, all the way across the barn and dropped them down to the floor below, an incredible fall for a tiny chick.  I found them huddled under Mom at the foot of the hay mow ladder.  Matt helped me gather Mom and chicks and put them in a rabbit cage in the heated room adjacent to the apartment (also called Kitty City).   With temps going down to single digits at night I don't know how long the chicks would survive, even with a very doting mother stopping to heat them up under her feathers periodically.  This way I can protect them from the cold and cats and make sure they get water and feed.  I pull all the eggs from the ducks (6 today!) and ladies in the chicken room, but I have no control over the free range girls who want to hatch eggs in hidden places.