Here’s what else you need to think about:
Depending on the breed of chicken, their combs and wattles can become frostbitten. Birds with large combs (usually breeds originating from a warmer place, such as Leghorns) are more susceptible to frostbitten combs and wattles, which can be quite painful. Birds with smaller combs and wattles usually sail through most weather just fine. Dampness is the real culprit in causing frostbite, so keep things dry. Some folks try spreading Vaseline or other oil on the comb to prevent frostbite, but it has never worked for me.
If you keep your water inside the coop during the cold months, pay extra attention to this area and keep any damp shavings cleaned up. If your birds are outside during the day–especially in the snow–they will most likely track snow back into the coop, so watch for wet or muddy shavings that might contribute to dampness in the coop.
And don’t forget to keep an eye on their feet and toes, which also can become frostbitten. This isn’t as common, but does happen.
I remember the very first winter I had chickens: I had to cancel a dinner party one freezing cold Sunday evening after going out in the afternoon and noticing that two of the hens, who had had long, thin red combs, were flinging blood from the frozen tips of their comb. I panicked and ran immediately to the hardware store for a heat lamp.
Some say never heat the coop. Others heat at the slightest edge of cold. I fall somewhere in the less-heat side, tending toward only heating if it gets REALLY cold. The cut-off point for me is 10 above zero and colder, because I do have chickens that are not super cold-hardy and have large combs that can get frostbitten fairly easily. If I had a larger breed with small combs, I’d probably never heat at all.
So if you have a large, cold-hardy breed of chicken, they usually are just fine as long as they have a dry, draft-free coop to get out of the wind and snow. If you really want to use a heating device, such as a heat lamp, be sure to tie it securely to prevent it falling and causing a fire. Because, it can cause a fire if it falls into shavings or touches any burnable surface. Sadly, I’ve seen stories in the news all too many times of families losing their entire flock because of a fire caused by a heat lamp. Also, place it somewhere above your birds so they cannot “snuggle” into the light bulb. I’ve had birds with singed feathers more than once.
A safer alternative might be a oil-filled enclosed radiator, the kind that turns off if tipped over. I’ve also seen ceramic radiant heaters that don’t involve light and can work well without a fire hazard.
Chickens also need plenty of clean, fresh water at all times in the winter as well as the summer. I use two different methods of keeping the water clean and unfrozen. In some of my pens, I use a plug-in heated dog dishes, which saves a lot of time instead of cracking the ice and adding warm water to the buckets twice a day in the coldest weather. In other pens, I use a stock-tank heater that I put directly into a black rubber pan of water.
The heated dog dishes do fine for a year or two, but I’ve found they stop working after a while. And, I have to store them over the summer, which takes up extra space. So as they break, I buy the small tank heaters that you simply drop in a bowl to replace them. I like the thick-rubber black pans that you’ll find at a farm store, as they don’t crack in the cold and you can easily turn them upside down and push out the ice in case they do freeze over.
Make sure your chickens have plenty of food to maintain their body weight in the cold. Extra feed, some cakes of suet filled with nuts or fruit, or even plain cracked corn can give your birds a much-needed caloric boost. I throw a handful of corn in the coop in the evening, which helps turn over the bedding and gives the birds a carb-filled snack before hitting the roost.