How much cold can a bald chicken take?

[MaeM]

I agree that does look like its from the saddle especially because of the rubbing on the shoulders. Sometimes even well fitting saddles can rub, especially if her back was already bare. Saddles work best when there are some feathers to sit on since that keeps them elevated.
I haven't made any saddles, but @OneMountainAcres sells them.
Are you using a flannel or outdoor type fabric? When I've tried to make my own saddles in the past, sometimes I put fleece or felt on the inside for hens who I was concerned about rubbing. Maybe you could try that?
Honestly, I'd probably just keep it off. Its easier for them to preen without them etc. If you're worried about chilling through you could probably try the fleece. My saddles never stayed on, so I'd love to hear how it worked.
Thanks for the tag @Crazy Maizie.

I used a thin fabric because it was hot at the time I felt the hen needed a saddle. I don't know exactly what fabric it is but it doesn't seem to be 100% cotton like a normal T-shirt, for example. It's less soft than a normal cotton T-shirt but not as rough as other fabrics I've seen. Sorry, I don't know much about this!

But if you've used felt and fleece, my lady probably needs something even softer. It's just that felt and fleece look too warm for a chicken who lives in a place where it doesn't even snow.

I'm not only concerned about the cold, though. Sometimes I see her skin gets red, like irritated, from not having any protection against anything.

Do you think I should take her to the vet? I don't think he knows anything about saddles, but I don't know what to do with her continuous baldness. If at least I saw enough pin feathers on her...

Another question: could she be plucking herself? I've seen her with her beak on that bare back but I don't know if she is trying to preen or plucking herself. I've read somewhere that broody hens may pluck themselves?

 

[Weeg]

Do you think I should take her to the vet? I don't think he knows anything about saddles, but I don't know what to do with her continuous baldness. If at least I saw enough pin feathers on her...

Another question: could she be plucking herself? I've seen her with her beak on that bare back but I don't know if she is trying to preen or plucking herself. I've read somewhere that broody hens may pluck themselves?

I don't think that a vet would have any insight on feather loss unless it was from mites/lice. Did you check them for mites or lice? Simply part the feathers and look for eggs/bugs. You can check for mites at night which will come out and crawl over their faces.

If a protein deficiency is an issue, than they could be feather plucking because of it. Is it only this girl though? If no other birds are showing any signs, then I bet its the saddle.
I think we determined that a rooster was the original cause. I think that the saddle is the reason for loosing more feathers. I would just remove it. I know what your talking about with the red skin, by her next molt she should start to regrown feathers, but I doubt she will before then.

 

[Weeg]

Another question: could she be plucking herself? I've seen her with her beak on that bare back but I don't know if she is trying to preen or plucking herself. I've read somewhere that broody hens may pluck themselves?

She may have just been preening. Like I mentioned in the previous post, a protein deficiency could be the cause. What % of protein is your feed? Since its only this girl I bet its the saddle causing the further issues.
Broodys pluck their breast feathers to use for their nest. This also gives the eggs and chicks direct contact to her warm skin. Broody's wont pluck themselves like your hen is in the photos.

 

[Crazy Maizie]

I just want to add that seeing the skin get red is normal when there is feather loss. They can get a sunburn, windburn, or just normal fluctuations that you wouldn't see if she had feathers.

 

[Kypris]

I would second the motion to feed her some feather fixer or other higher protein feed to help her grow those feathers back. We had this happen last year with one of our hens and we did a combo of higher protein feed and a hen saddle and the feathers grew back after she had been totally bald for a few months and laying eggs with no shell or very weak shells. She's doing great now a year later....no more feather loss. In her case it could have been bullying because we were without a rooster for a few months and they didn't grow back on their own.