Windshield wipers not working in extreme cold weather.

What is your question?

It seems my wipers don't work when the weather is in the single numbers or below zero. When I go to turn them on, I don't hear the motor at all. It seems when the either the car warms up for a while or the weather is warmer They come on. This is the first time this has happened since I owned the car and I have had it since 2003. Do I need to change the wiper motor? The wipers are not frozen to the windshield.