Returning to my car from the theater with my wife one winter night, I was annoyed to find my (driver's side) door lock frozen over.
Cursed, tugged, even torched it a bit with a bic. No joy. Just when I was ready to look over the top of my car to my wife, the door opened.... "what are you doing out there, she said".

Seems as if HER door was fine. She got in, sat down, and waited to see why I was dancing about in the cold. When she got bored, she pushed open my door from the inside. No problem. Much humiliation, though.