Good points on the deep litter. I had forgotten to mention the extra microbes and keeping down the parasites. Reading from
Storey's Guide to Raising Chickens this morning pointed out the wonders of the deep litter method. It sounds so wonderful, I want to find a way to make it work.
Although I live in an area with houses surrounded by brick walls, I am fortunate that my property was landscaped for some privacy. I have 15-20' oleanders surrounding the entire backyard fence line. When I run my sprinkler's my entire yard drops several degrees and it feel so much better. Amazingly, the couple of fans on the back porch manage to drop that temperature even more. Even so, my coop is placed along the wall of the house, under the shade of the porch. I would much rather it be always shaded and allow them to be accustomed to the cold than to have to fight the heat. As I always say, you can always put more clothes on, but you can only take so much off before it becomes indecent. Of course, that's a whole lot sooner for some of ugly folks...
This seems to hold especially true for the chickens. Look at the old stories and they are raising them in -30* weather with no more than insulating a proper coop. No heater and all the fancy stuff.