How long has she been inside? Do you have a cooler room or garage to keep her in? Chickens don't get colds, but they can get respiratory diseases such as infectious bronchitis, MG and others. While heat may help a sick chicken, too much can make them pant, and it can increase the probability for respiratory symptoms. Make sure that she has good air circulation and cooler air. If she appears very sick with her respiratory symptoms, though, she may still require some extra warmth. But first I would either place her back in her coop in a dog crate with food and water, or place her in a cool place, such as a garage or basement. Many diseases are viruses, so antibiotics may not be necessary. MG and some others, may be helped with Tylan 50 injectable used orally.