On a recent subzero night, firefighters in the Chicago area were dispatched to three homes where people had used flame devices to thaw frozen pipes.

Using an open flame to try to thaw frozen pipes would seem to be well-established as a poor and perilous decision. But people keep doing it.

The fire department in Waukegan. Ill., presented the topic of frozen pipes as a trivia test on its Facebook page, posing the question of whether the following are safe to use to thaw out pipes: wrapping towels or insulation around them, blowing with a hairdryer or using a propane heater, blowtorch or other open flame.

Towels, insulation and hairdryers are good. Anything involving a flame: bad.

Fire safety experts say preventing pipes from freezing is significantly easier than dealing with a frozen or cracked pipe. And, to get in front of the problem, the emphasis should be on keeping warmer air circulating around the plumbing.

Opening cabinet doors — under kitchen or bathroom sinks, for example — is one way to help prevent frozen pipes, experts say. Maintaining a consistent temperature in the home is another. If you're going to be away from home during a deep freeze, the American Red Cross recommends setting the interior temperature no lower than 55 degrees.

Another long-held preventive strategy is running faucets at a trickle or drip.

In addition, heating tape and insulation, products available at many hardware stores, can be wrapped around pipes to prevent them from freezing.

The most vulnerable pipes run along exterior walls or to an outdoor spigot or through a home's foundation. If a house has living quarters with a bathroom above a garage, pipes in that bathroom or kitchen also can freeze if the main garage door remains open for long.

Outdoor spigots, swimming pool lines, water sprinkler lines and fire suppression sprinkler systems — particularly those in vestibules — also are known to freeze in fiercely cold conditions.

Once a pipe has frozen, it can be thawed using a few approaches. The Red Cross recommends keeping the faucet open and applying heat with an electric heating pad wrapped around the pipe, an electric hairdryer or portable space heater or by wrapping pipes with towels soaked in hot water.