Is my chicken unwell or just feeling the cold?

[Equiem]

Well, without any other symptoms, all you can really do is monitor her for several days.
See that the crop is empty in the mornings, that she's lice/mite free and that she's eating/drinking well.

Hope all goes well for you

Turns out she was unwell
Her health started to decline - her comb began to get floppy and pale, she went off her food (she always loved her food) and she stopped being "her usual self"
She was putting lots of energy into growing some new feathers too
I took her to the vets this evening and they aspirated a bloody fluid from her abdomen which unfortunately, sealed her fate.
I know we shouldn't have favourites but she was mine, partly because she was the only one left that didn't mind being held!
Not all things bad have come from her passing though, I will be rescuing some more ex-battery hens at the end of the month to give them the life I gave her - being loved and spoilt!