Heat lamps are extremely dangerous. I have read so many stories about people's barns burnng down from well intentioned owners leaving heatlamps on all night for newborn animals or chicks.Thanks for your advice, but we don't put a heat lamp in the coop because what if the power were to go out in the coop? The birds would be so used to the heat, that they'd die from the lack of it. It is a good idea though.
We use heat lamps for chicks in pens, or if the weather is dangerously cold...in the single digits and below...but we always turn the heat lamps off before we go to bed...no exceptions..check on them often throughout the day while they are on, and try to position them so if they fall off or explode, that the hot surfaces will not easily ignite anything. They do make cool blue heat lamps, but I am not sure how those work, I have never found any though I haven't looked on line. Insulating the coop, or wherever they are sleeping, helps. I have read that vaseline just makes the combs cold, and I'm sure that's true. We don't use vaseline because we can't catch most of our roosters, and they are primarily the ones who suffer from frostbite, because they don't usually sleep with their head under a wing. At night, the birds will huddle together, or mama will keep the chicks warm, and in a well insulated building, or even one not so well insulated, all those feathery bodies will generate a surprising amount of heat for all to share...