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. Be sure to move any harmful cleaners and household chemicals out of the reach of children. When the weather is very cold outside, let the cold water drip from the faucet served by exposed pipes. Running water through the pipe, even at a trickle, helps prevent frozen pipes.