Mr. Freeze Locks

I have been having some lock problems for a 94 buick regal. Recently, it has been cold here in Chicago and I was able to put my key in the hole and turn the key but when I go to use the handle, it goes flimsy and won't open. Same thing for the passenger side. What ended up happening was the metal cracked on the handle from the inside. I got it replaced. As of today, the same thing happened. I put the key in hole, turned it and went to grab the handle, it turned flimsy. At first I thought it broke again, but I called a mechanic of ours and he came over and unscrewed the cover of the handle. Nothing cracked but it was just frozen. How could I get not from freezing again? I keep my car out and not in a driveway. Help!! After sitting in the sun, both doors unfroze and now I have to keep them unlocked.

spray some lubricant (wd-40 or something) on it when it's dry and thawed. That should take care of it.