Whether your water comes from a well or the city, it enters your house cold.
Preventing this cold water from turning to ice in the pipes closest to the inlet of water takes a small amount of work, but can save expensive repairs should a pipe freeze and break.
Determine where the inlet pipe is. If you have an outside hose, chances are good that the inlet pipe is closeby.
Where the inlet pipe enters the house is the coldest and most vulnerable area for freezing pipes. Standing water, especially at night, can freeze easily in small pipes.
Option 1: Heat tape. Heat tape plugs into an outlet and draws a small amount of current to warm the pipe for a short distance (usually far enough from the wall to prevent freezing). You simply wrap it around the pipe and plug it in. A thermostat keeps it from overheating. The downfall? Power outages.
Option 2: Insulated pipe jacketing. Pipe jacketing looks like a long sponge-like tube, but it has a slit along the side. You simply cut it to the lengths you need and apply electrical tape to hold it securely. The downfall is that the inlet pipe may not be insulated close enough to the wall. Pack fiberglass insulation securely around the inlet pipe as tightly as possible.
Option 3 is to hang a construction work light close to, but not touching, the inlet pipe on the coldest of nights. The heat from the lamp will be enough to keep the pipe from freezing.