They say that prevention is the best medicine, and in this case, it’s definitely true.
Your best defense against freezing locks is to spray a little WD-40 or graphite-based lubricant on the lock early in the winter driving season. (You may want to reapply occasionally.)
If your locks DO freeze, however, there are a few things you can try:
• It may seem obvious, but check and see if any of your other door locks are in working order. If you are able to get in your car through another door, turn the car on and let it warm up for a few minutes before you try to open the door that is stuck.
• Use an aerosol de-icer, available at many hardware and automotive stores. (Once again, planning ahead is essential. Many people make the mistake of keeping these commercial de-icers in their cars, but if your locks are already frozen, this won’t do. Instead, keep a can at home and maybe even in your desk drawer at work.)
• If you don’t have any de-icer handy, you can place your thumb or hand firmly against the lock and hold it in place for a few minutes. You may have frosty fingers (hopefully you’re wearing gloves), but it just may do the trick.