How cold of weather can a chicken or rooster withstand?

I have chickens and they can usually stand up to around 10-15 degrees. My roosters' combs usually get frost-bitten though if the weather is that cold.

I have had Roosters, Chickens, Snow Geese, Guinea's, Pheasants, Ducks, Peacocks, over 1000, in chicken houses, corn cribs, some caged together, all of which, had at least 8 [or more] light bulbs heating the air to a point where they cuddled together for warmth under them, 10 to 30 below, in the worst winters. Yes they can die from exposure, but usually it would be the young ones, so you must make sure they get heated lamps in their enclosure. The water feeders must have electirc warmers, or you will be changing their frozen water dishes often and that in and of itself, is so important. Add a couple drops of iodine into their water to fight off germs protect them from getting sick-JUST A COUPLE DROPS! Consult a current "FARMER'S ALMANAC", for great tips and hints for care, as it is a reliable source we used as our "BIBLE" of information, for all our livestick.