We left town in time for a cold snap, and last night, after a week of 40-50 below temperatures, my house-sitter went out to check on the hens, and found blood everywhere, found the affected bird, and took her in the house to clean her, inspect her, and call me. The eventual diagnosis was a broken toenail. (A little blood goes a long way!) She's clotted over, acting fine, and back in the coop with her buddies now, and I am grateful that I have a house-sitter that cares for my birds even when it isn't all that fun. I think I owe her a bonus! Today, the temp is up to a balmy minus 5. Much nicer!