Yes, fire is used to keep Chicago trains running in the cold

[mahatmakanejeeves]

2. Here's another article, but the author doesn't know a lot about railroads.

It's a rewrite of the Chicago Tribune article, but he mashes the thoughts together.

TRANSPORTATION
Chicago Is So Ridiculously Cold That the Railroad Tracks Need to Be on Fire to Keep the Trains Moving

Bradley Brownell
Yesterday 10:00pm Filed to: TRAINLOPNIK

There are over 140,000 miles of privately-owned standard-gauge rail in the United States, vital to the transportation of billions of tons of freight and people. Occasionally, it gets really cold where some of those train tracks sit. Like right now, in Chicago, where Wednesday’s high temperature is expected to be thirteen degrees below zero. Those temperatures are potentially deadly for humans, and deforming for the long pieces of metal that trains ride on.

When it gets to be several degrees below freezing, the metal of the train tracks can contract to the point that it will pull up the bolts holding it in place, or even stress fracture. Crews will soak long pieces of rope in kerosene and burn it to warm up the tracks, expanding them back into place for repairs. Once the track is warmed, it’ll be re-bolted, or welding repairs can be affected on the broken tracks. This is vital to continued operation during cold temperatures.
....

Not quite....

This commenter threw in a nifty video:

Guacamoldy! > Bradley Brownell
1/29/19 10:20pm

For what it’s worth, those burns in the switchyards (in the ABC tweet) are gas burners, not kerosene ropes. Actually quite nifty (and if you’re a particularly daredevilish drifter-type, you can heat up your can of beans on them).

About that video:

Metra Commuter Rail
Published on Feb 23, 2018

Video of the gas-fed switch heaters at the A2 interlocking in Chicago.