About all they need is a draft-free enviroment but if it gets as cold this winter as it did last hanging a heat lamp wouldn't hurt either. Even in winter they will need ventilation to keep humidity from building up.
We have covered bantam pens with heavy drapes, (garage sale find) and I have duct taped shower curtains over pens to cut the wind as well.
If power goes out while brooding just cover the brooder with blankets for short term. Long term outages they will need a back-up source of heat. We have a generator that can be hooked up but I would hate to feed that thing at today's gas prices!
Feather legged breeds from my experiance don't do as well as the clean legged breeds do as far as their feet and toes freezing and as Carl has mentioned the Modern Games can freeze their legs easily.
The roosts should be a 2x4 laid flat, that way when they roost and settle they cover their toes with the breast and keep them warm. A hen will seldom get a frozen comb because she will tuck here head under her wing while it is rare for a rooster to tuck their heads and so their combs can freeze.
Then there is the need to keep fresh unfrozen water to them. You can buy heated water bases or even heated waterers.
And here is what I think is the most important thing to do if you hang a heat lamp, NEVER use the clamp on the base to hold the light. ALWAYS use a chain that is securely nailed or screwed into something substantial. The light can fall and cause a fire if it falls into bedding of any kind.
Also keep at least one spare heat lamp bulb. Ever try to find one on Christmas Eve about midnight? It wasn't fun.
