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

When the weather is so dangerously cold that may harm your health, safety rules should be obeyed everywhere. Even in railways.

Chicago is in the cold spell and all trains from and to the city were stopped from moving earlier. But Chicago residents know how to keep things moving when it is 50 below zero cold. Fire flames were seen through the railways on Tuesday.

“The flames actually come from gas-fed heaters that run alongside the rails and keep them warm,” spokesman of Chicago’s Metra commuter rail system Michael Gillis said. “”Anytime it’s below freezing were using these,” added Gillis.

This measure was taken because train tracks are affected by extreme cold. Usually they are affected in two ways.

First way is called “pull-aparts”, which occurs when two rails het separate at their connection. The extremely cold weather shrinks the metal so that rails pull apart from each other.

Second way is that railways could be clogged with ice and snow. In below zero temperature it could pose a real threat on trains movement.

So the heating system is used to avoid any consequences from been hearted, especialy by these two types of damages. Certainly, heating may damage the railroad as well, but this is safer method. Thus maintenance crews used pots filled with kerosene, and lit them by hand previously stuck them in spaces between the track ties.