Keep the outside valve open so that any water remaining in the pipe can expand without causing the pipe to break. Check around the home for other areas where water supply lines are located in unheated areas. Look in the basement, crawl space, attic, garage, and under kitchen and bathroom cabinets. Both hot and cold water pipes in these areas should be insulated. A hot water supply line can freeze just as a cold water supply line can freeze if water is not running through the pipe, and the water temperature becomes cold.
Many products are available at a building supplies retailer.
Pipes should be carefully wrapped, with ends butted tightly and joints wrapped with tape. Follow manufacturer's recommendations for installing and using these products. Newspaper can provide some degree of insulation and protection to exposed pipes. During Cold Weather Take Preventive Action Keep garage doors closed if there are water supply lines in the garage. Open kitchen and bathroom cabinet doors to allow warmer air to circulate around the plumbing.