When I let the chickens out this morning, I noticed one sitting off by itself, all puffed up with her head pulled way in. I tried giving her treats, but she wasn't interested, so I took her in the house to go into the "Sick" box to see if she would improve with some heat. It was below 30 F last night, so I thought maybe she was cold. I gave her warm water with electrolytes and vitamins and a cooked egg yolk. She seems very light, not heavy enough for her size. I don't know what her droppings are like because I had to go to school, and she didn't have any before I left. I lost another hen with very similar symptoms a couple of months ago. I never determined what was wrong with her, she just sat there for days in the sick box, ignoring all food and drinking very little, until she died. I would really like to not lose another one, since these were some of my only true Americanas, and they're not even laying eggs yet. This hen is about 16-18 weeks old. Thank you everyone for reading this and for any suggestions.