Well, not sure where you are located, but my chickens are are Everett WA. Our winters... and summers are rather mild. Our cold cold is probably a week or two of nights in the 20's, with 2-7 days of snow annually that might stick for a day to a week or so unless it is a harsh cold winter like two? years ago when snow stuck for like two weeks!
That said... I've not had frozen toes, birds, combs or such from birds sleeping outside, but I keep mostly standards and my rooster was a rose comb bird. So in short, sleeping outside has not been any health issue for over a decade of chicken keeping, since 1998 if my memory serves.
Indoors without enough ventilation would be way worse than outdoors with lower humidity. High humidity + cold = frost bite easier.
That said... I've not had frozen toes, birds, combs or such from birds sleeping outside, but I keep mostly standards and my rooster was a rose comb bird. So in short, sleeping outside has not been any health issue for over a decade of chicken keeping, since 1998 if my memory serves.
Indoors without enough ventilation would be way worse than outdoors with lower humidity. High humidity + cold = frost bite easier.
