Sick Chicken! Tail feathers are down, not moving, seems to be panting.

[Wyorp Rock]

One thing not mentioned/asked - what does her crop feel like? Check to make sure it's empty by morning before she eats/drinks.

 

[rebrascora]

I would cut the scratch and corn from her diet altogether. She is potentially showing symptoms of Fatty Liver which could prove fatal and those foods can cause that ailment. Not saying that's what it is, but it will do no harm to cut them out not just for her but also the rest of the flock, at least for the time being and perhaps a vitamin B supplement to support her liver. Provide only layer feed and a few bits of fruit and veg but no other starchy/carbohydrate treats. Drinking but not eating could be due to a crop issue or could be due to internal haemorrhaging or it could just be due to the heat. It is not surprising that she is a little more comfortable on an evening when the heat of the day is subsiding a bit.