"It's never been minus 50 in Chicago, so we can't really say it "feels like" - nobody really knows what that feels like", Abrams said.
"A record cold air mass will continue into the central and northern U.S., spreading to the east coast on Tuesday", the NWS said.
In Minnesota, wind chills as cold as negative 54 degrees Fahrenheit were reported Wednesday, while Minneapolis was hit with negative 52-degree cold. In Chicago, temperatures were still dropping after plunging early on Wednesday to -28C, breaking the day's previous record low set in 1966 - and colder than the weather in Barrow, Alaska, the most northern town in the US. Her chickens, ducks and guinea hens were enjoying the 70-degree (21C) climate inside their greenhouse-like hoop house, she said. One-to-two feet of snow was forecast in Wisconsin, and six inches in IL.
"The Midwest and Great Lakes are well into this Arctic blast, with dangerously low wind chills widespread across the region this morning", meteorologist Janice Dean announced this week on "Fox and Friends".
Parts of north and central Georgia may see about 2 inches (5 cm) or more of snow in the coming days, along with freezing rain and ice-slicked highways.
Governors in Wisconsin, Illinois and MI declared emergencies as the worst of the cold threatened.
US homes and businesses used record amounts of natural gas for heating on Wednesday, according to preliminary results from financial data provider Refinitiv. By 7 a.m., temperatures were down to minus 23 degrees Fahrenheit (minus 30 degrees Celsius) at O'Hare International Airport, according to NWS.
Atlanta-based Delta Air Lines Inc said it would waive flight change fees for passengers affected by the winter weather in Chicago, Detroit and areas of the Upper Midwest.
The mercury fell to as low as minus 18 deg C in Chicago, while the temperatures tumbled to a frigid minus 29 deg C in Minneapolis.
Officials in Chicago, which has the nation's third-largest school system, said classes would be canceled focancelled0,000 students on Wednesday due to the severe weather. Schools and colleges have temporarily closed in many parts of the Midwest, and the Postal Service has effectively canceled Wednesday mail delivery in parts of at least 10 states out of concerns for the safety of employees.
It's also now colder than Mars. "Extreme and risky COLD!"
He said ambulance crews were handling all outside response incidents as being potentially life-threatening.
Hundreds of warming centres were opened for vulnerable residents such as seniors, buses were employed as mobile warming spaces, and shelter capacities were increased for the homeless, including the approximately 16,000 living on the streets of Chicago. He also urged residents to check on their neighbors and take safety precautions. It is called "sudden stratospheric warming".
The brutal chill was caused by the polar vortex, a mass of freezing air that normally spins around the North Pole, but has made its way south into the US.