Here are a few tips to help you prevent frozen pipes:
Open cupboard doors under kitchen and bath sinks to help heat circulate around plumbing.
Leave water running just slightly - about a pencils width stream.
If you normally turn your heat down at night, or during the workday while you're away, don't do this during extreme cold.
Make sure all foundation vents are closed. If you have heat tape on pipes make sure it is plugged in.