Courtesy of The Courier-Journal:
• Wrap insulating material around exposed pipes such as those under kitchen sinks, in crawl spaces, near windows or in unheated basements.
• Locate and tag the water shutoff valve in your home. Knowing where the valve is and how to shut it off can help prevent water damage in the case of a burst pipe. The shutoff valve is typically in the basement, under a kitchen sink, in a utility closet, near the hot water heater or in a crawl space.
• In homes with crawl spaces, cover outside vents to prevent winds from entering and freezing pipes. The doors of garages with concrete slab foundations should be kept closed since some water pipes are located under those floors.
• Disconnect the hose from the outdoor water spigot and shut off flow to the outdoor spigot.
• As a temporary measure, allow water to drip from a sink during periods of extreme cold. The flowing water will prevent the pipes from freezing.
Source: Louisville Water Company, Dauenhauer Plumbing