I agree, if you're in Phoenix I would get a humidifier.

We recently went to Denver, which isn't as dry as Phoenix but is still dry, and the first day I'm there I can just about feel my skin drying out and starting to crack. I really have to slather on the moisterizer otherwise I'd be just one big flake of dry skin while I'm there. I don't know how you do it in Phoenix without a humidifier.