Chicago crews are using fire along the city’s commuter railroad track to keep the switches from freezing as the city is plunged into record-breaking frigid temperatures.

The cold weather, snow and ice clog the switches, leading to halted trains and severe delays in service, the Chicago Tribune reported Wednesday.

ADVERTISEMENT

Metro workers are using a gas-fed system to generate heat along the tracks where the switches meet to combat the subzero temperatures. The system is also used during normal winter weather.

Extreme cold weather can cause the steel to contract and break along the crossings where the rails are bolted together, Metro spokeswoman Meg Thomas-Reile told the Tribune.

Once the fire heats up the rail enough to expand again, workers onsite can rebolt or weld the rails back together.

Chicago and other parts areas of the Midwest are expected to have some of the coldest days on record as the polar vortex brings temperatures typically seen in some of the globe’s coldest places, such as Antarctica, Mount Everest and Siberia.

A record low temperature for Jan. 30 was set for the city by 2 a.m. as temperatures dropped to 16 degrees below zero. Temperatures for the day are expected to peak at about 11 to 15 degrees below zero before dropping to -27 degrees overnight.

The predicted low of 27 degrees below zero at O’Hare International Airport for Thursday would reportedly match the city’s all-time record low temperature.

Temperatures are not expected to return to normal highs in Chicago until Saturday.

Illinois Gov. J.B. Pritzker (D), as well as the governors of Michigan and Wisconsin, issued disaster proclamations to provide resources to officials responding to the temperatures.

We are facing potentially historic weather in Illinois. I’m issuing a disaster proclamation so that the State of Illinois can use every tool at our disposal to provide relief to our residents and keep them safe. https://t.co/oxN5UAEWL4 pic.twitter.com/p9G139bzxX — Governor JB Pritzker (@GovPritzker) January 29, 2019

An estimated 19,000 ComEd electric customers were left without power, the Tribune reported Wednesday morning.

The U.S. Postal Service and Amtrak trains have suspended service, and schools throughout the region are closed until at least Thursday.