It's not always about the cold - like the guy from Michigan said, the culprit for him was sand. That sounds like much more of a bugger to deal with...How cold is it????? Try heat gun, hair dryer, or propane torch (Be CAREFUL!).
Also, if you are tapping with a hammer, use a small tack hammer together with your Liquid Wrench (or whatever product you have). Tap, tap, tap away! The smaller hammer sets up higher frequency vibrations that work better to 'unseize' stuck things.