AZ Cold Weather & Chickens

Oh my gosh!! It is supposed to get into the mid 20's tonite & that is a rare occurrence here in Arizona. My littlest chickens that are a few months old are under a heat lamp, with plenty of deep bedding. I think they should be fine. The other 3 are roosting up at the top of the coop near the eaves next to another heat lamp and I am pretty sure they should be fine. We have a white silkie bantam, and the silkies cannot fly. Their wings are just too short. This one, her name is Bambi, usually burrows down into a little hole she has dug out. I am worried she won't be fine. I tried to move her in with the little chickens, but she just wants to peck at them, which isn't good. I finally ended up moving her into an enclosable section of the coop where there won't be a draft and there is plenty of deep bedding. I won't like it much if I go out there and find chicken popsicle in the am! (JK...kind of terrible I know...all I can say is my husband's humor must be rubbing off after 22 years.) Can you tell I obsess, just a little?