Ok, chicken experts, I need your advice! I recently acquired two new hens, and I had to bring one inside to treat her for a severe lice infestation (she's a crossbeak, so she wasn't grooming herself like the others - I discovered the lice when I brought her in to give her a bath). Now that she's back to normal and the lice are dead, I need to get her back outside with the other girls. She's currently in a large dog crate in a spare bedroom, which is probably 60-something degrees (it's a little cooler than the rest of the house). I know chickens need to be acclimated to the cold, so I'm wondering - how cold is too cold to bring her back outside? Right now, we're having highs in the 20s-30s and lows in the teens and single digits. How warm should it be before I let her out? My girls free range my backyard all day, so I feel bad that she's trapped inside!