If you've had the unfortunate pleasure of stepping outside this week, you may have noticed something strange happening on Chicago's Metra train tracks: They're on fire. No, the city isn't burning down in some weird Polar Vortex-induced blaze. There's a much more logical (and far less morbid) explanation.
In the same way that snow and extreme cold affect roads and highways, sub-zero temperatures can negatively impact railroads. Switch points along the track can get clogged with ice and snow, which makes it impossible for trains to run, causing serious delays. Metra keeps things moving with the help of fire.
The flames you see come from a gas system that runs along the rails, not on them. The controlled burn helps keep switch points from freezing, which allows trains to pass through without issue. According to Metra, there are instances where the flames can't keep up with heavy snowfall or intense cold. When that happens, workers clear the switches with shovels, brooms and picks. (Talk about the coldest job in Chicago.)
Check out this video to see Metra's seriously awesome—and totally safe—fire-fighting measures at work.