Many people were urged to stay home, and those who did venture out were advised by the National Weather Service to cover their mouths and protect their lungs from severely cold air by not "taking deep breaths" and keeping talking to a minimum.
The Arctic cold is all but certain to break records, but could be truly historic in IL. The number of deaths that could be blamed on the cold climbed to at least 15.
"A record cold air mass will continue into the central and northern U.S., spreading to the east coast on Tuesday", the NWS said.
Schools and businesses remained closed in several Midwestern states, people were encouraged to stay home, and travellers were stranded by grounded flights and halted trains.
Authorities in MI and Minnesota were also asking residents to turn down their thermostats to conserve natural gas.
Natural gas supplies were under threat in MI and Minnesota, where authorities asked residents to reduce their heat consumption if at all possible.
On Tuesday, Amtrak announced that it had canceled all rail service to and from Chicago Wednesday.
Authorities warned that the extreme temperatures were life-threatening, as Illinois, Michigan, and Wisconsin implemented emergency measures.
"We are not done yet".
Places like Chicago and MI got the brunt of the arctic winds, with parts of Chicago that are colder than parts of Antarctica.
And that doesn't include wind chill, which in northern IL made the air feel as cold as negative 57 degrees (negative 49.4 Celsius). The weather station at the Moline Quad-City Airport sent a reading of minus-29 degrees at 11:19 p.m., which was enough to break the record, and then continued to drop even further through the early-morning hours Thursday. The record low of -27F (-33C) was on January 20, 1985.
Wisconsin and MI have declaried a state of emergency, with many state agencies closed in IL as well.
Dozens of records could be broken this week as the temperatures fall.
'These are VERY DANGEROUS conditions and can lead to frostbite on exposed skin in as little as five minutes where wind chill values are below -50, ' the National Weather Service office near Minneapolis tweeted.
America's northern neighbour Canada was also contending with extreme cold, with frozen water pipes and snarled travel on a major waterway.
Chicago´s regional electric train service was canceled due to wire problems caused by the freezing temperatures, as gas burners heated rail switches to keep trains moving on a reduced schedule. Unlike many other news organizations, we have not put up a paywall.
Hundreds of warming centres were opened for vulnerable residents such as seniors, and shelter capacities increased for the homeless. Of course, it's more involved than that: a big storm system turns into three separate superstorms that cause things to flash-freeze at temperatures of -150 degrees.
Some residents just to the north and northwest of the Twin Cities in Minnesota were asked by Xcel Energy to dial down their thermostats to 60 F (16 C) because of the strains on its natural gas supply system.
General Motors and Fiat Chrysler suspended or curtailed operations at more than a dozen facilities in MI to conserve natural gas, the companies said. Crews in Detroit will need days to fix water mains that burst Wednesday.