FARGO — Commuter rail workers in Chicago have taken to setting tracks on fire to keep trains running smoothly, but on the frigid upper Great Plains, railroads have a more sophisticated way to keep track switches working.

When temperatures drop well below zero, it can be tough for metal track switches to move. To keep trains headed in the right direction, railroads need to clear ice and snow that might be stuck in switches.

But in North Dakota and Minnesota, there's no need for workers to torch the tracks. Instead, propane-fueled switch heaters blow hot air on the tracks to thaw them out.

BNSF Railway said it has about 3,000 switch heaters on its freight rail lines across the country. The railway said it performs additional track inspections in extreme temperatures, both high and low.