I've been reading quite a few posts lately that say "high" humidity in a coop will contribute to/cause frostbite in chickens. I'm wondering where this idea comes from and if there is any evidence to support it. I think that in warmer weather humidity can be a problem if the coop is not ventilated well enough because it might contribute to the buildup of ammonia. In weather cold enough for frostbite I don't think humidity would be that much of a problem because in extreme cold air the humidity cannot get that high. The colder the amibient air temperature the lower the humidity. The water vapor freezes out of the air. You can't have high humidity in cold temperatures. This is based on the amount of water in a given volume of air rather than the percentage value of relative humidity. http://en.wikipedia.org/wiki/Relative_humidity See the table about 3/4 down the page.