Yes. I have lost birds to "cold" before. Someone else mentioned that hardy, healthy, acclimated birds with enough food and no underlying conditions would be fine. I am no expert, but I think that in extreme conditions, birds can get extremely stressed. Stress can lead to illness/death. Stressed birds don't eat and drink adequately. Birds who don't eat and drink enough in cold weather are not replenishing enough calories to stay warm, without enough calories birds will get weaker, as birds get weaker they won't eat and drink as much, you can see how this can be a downward spiral.
EXACTLY! This all stems from about a week ago. My neighbor also has chickens, 4 of them, who pretty much live at my place. I feed them everyday, while feeding my own flock and they don't cause any problems with my flock so I don't mind. But anyways, about a week ago, I returned home from the store to find my neighbor's hen, who I named "Penelope," standing in front of my coop, which was closed. It was sleeting/snowing, had been since the day before. It was around 10°F. She was not moving at all. The 3 of her fellow flock mates were all standing around her, leaning their heads up under here, as if they knew something was wrong. I called her name, still nothing. These are the kind of hens that run to your car when you pull in the drive, especially if they hear the noise of grocery bags lol which I was carrying in at the time. When I reached down to touch her back, she was soaked from the sleet and snow and her feathers were hard and frozen. She was very lethargic, barely moving at all, only to blink her eyes, that was about it. I carried her inside, dried her feathers off with a towel and let her warm up for a few. I took her back out, the neighbor was not home, so I put her in my coop. She wouldn't eat or drink, usually this hen is a gluten and eats right out of my hand. I sat her up on the roost on top of some straw bedding. She stood there, facing away from me. I went out a few hours later to check on her, she was still in the exact same position. For 3 days! She stayed standing on the roost. The 4th morning when I went out to the coop, she had finally warmed up enough to come down for breakfast. She drank a ton of water while I was out there too. Now, I know that her being left out in the snow with nowhere to go for shelter is what caused her near death experience, however I do believe that even the cold hardy, healthy breeds, who are exposed to EXTREMELY COLD temps, for weeks at a time like what we're going through now, can take a toll on these animals resulting in stress, sickness and even death. Yes, there are tons of chicken owners out there who I'm sure will disagree and say that they've never lost a bird to the "cold," and I believe you. But then you have chicken owners such as myself, and the original person who created this thread, among with numerous others who have commented, who indeed have witnessed, or experienced a death of their own due to the cold. I just feel like even when you do everything right in regards to ventilation, no drafts, no heat, proper nutrition, plenty of dry bedding changed daily, water removed before bed time, healthy birds, etc, etc, etc. Sometimes it's just inevitable. We can't stop mother nature. So to the original person who created this thread, I do believe that your silkie literally "froze to death." And I am very sorry for your loss. As a fellow silkie owner myself, when I seen that my 9 month old male silkies fur were both covered in ice, I was fortunate enough to be able to bring them inside, and I know that a lot of ppl aren't able to do this. I feel, that had I not brought them inside, I would have found them both dead too. Sorry for writing a book lol I'm done now.