About a month ago I went into our coop in the morning to feed our 14 hens and one was lying dead near the waterer. This happened after temps went from 60s to upper 20s overnight. I figured it was just a "one time thing". I looked the hen over, but didn't see anything unusual. She was a bit thin in the breast area, so I figured maybe a little undersized. Yesterday, as temps plummeted again, we had another hen dead. They've recently gone through a molting and I initially thought that it might be that their feathers hadn't fully come in and the cold snap got to them. Any ideas or things I could do to rule anything out? FWIW-they were just under 2 yrs old.