(CNN) Chicago residents are a hearty bunch. They know how to keep things moving when the weather turns cold.

But what about when it's this cold? Like wind-chill-of-50-below-zero cold? Getting around is lot tougher. When that happens, the folks who keep the commuter trains running in the Windy City employ a hot idea: They set the train tracks on fire.

Flames were seen sprouting from the tracks of Chicago's Metra commuter rail system on Tuesday.

Aerial footage shows train tracks set on fire to prevent freezing in Chicago.

Metra isn't literally setting the tracks ablaze, spokesman Michael Gillis told CNN. The flames actually come from gas-fed heaters that run alongside the rails and keep them warm. Metra also uses a tubular heating system and hot air blowers to heat up cold track.

"Anytime it's below freezing were using these," said Gillis, who said other rail systems in North America use similar systems.

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