Check your other chickens for the "bump"... every chicken has a "gland" above the tail.. it is narrow, small, about a half inch tall, just above the tail on their back...
How old are your chickens, how old was Zoe? How long was it since she had been stuck in between the bales? Had anyone been picking on her, other chickens bullying her?
Have you ever wormed the flock, when, with what, repeated? (Worms can cause a lot of symptoms, even limping, a loss of balance, and many, many other symptoms). Search "worming"... and "worming with Valbazen" here as well).
42 degrees is not cold.. search here.. you will find that people have chickens where there is snow and -20 degrees... and they don't use any heat until it gets to 0 degrees... and chickens are well insulted.. have "down" on them. If they have a coop and are protected from the wind that is the main thing. They have to have a place to get out of the weather and wind.
A hospital box is always good until any weak or sick chicken gets their strength back.. Zoe may have gotten dehydrated from being trapped -- unflavored Pedialyte is good for that as well.
Keeping any sick chicken that is full grown "warm" (that is a relative term)... separating them, putting them in a cage in the house, garage, etc... with a light for warmth if needed. If any weak or sick chicken is eating and drinking it's a good sign. If you have to give any chicken anything orally, be sure to search here on how to give oral medications, water, and food... so as to not get it into the windpipe.. avoid the airway when you give anything orally.
If a hen is eggbound and you have to give them the warm, massaging water bath, stay with them, hold and massage them while they are in the water -- keeping them upright, calm, warm, still. Search for symptoms of Eggbound... here on BYC. Mostly young and new layers get eggbound. In their first few months of laying.
I am very sorry for your loss..
Sorry you lost her. Hope all the rest do well. Take care.
