A cold snap so awful it’s being described as “life threatening” is gripping the upper Midwest and northeastern United States, and the next two days will usher in the region's lowest temperatures in two decades.  Most places will be well below zero – Many could see lows deeper than 20 degrees Celsius.

“The coldest weather in years will be making its presence known from the Upper Mid-West to the Mid-Atlantic region for the beginning of the work week,” the US National Weather Service said in a statement. “Combined with gusty winds, these temperatures will result in life-threatening wind chill values as low as (minus 51 degrees Celsius).”

The culprit is a “Polar Vortex”, a mass of cold, dense Arctic air that’s moving counterclockwise.  It’s caused massive snowfall and deep temperatures that have contributed to the deaths of at least 16 people so far.

As much as 20 centimeters of snow has already fallen from South Dakota through Illinois, and that system is heading to south states Tennessee and Kentucky that aren’t usually considered in the Snow Belt.  Atlanta in the Deep South will see lows temperature of 4 degrees below zero.

Several schools systems are canceling classes for Monday to protect kids from the potentially-deadly weather.  Minnesota Governor Mark Dayton cancelled classes for the entire state.  But some couldn’t get the job done without some unnecessary drama.

Earlier, the Chicago Public Schools insisted it would remain open on Monday, even though the morning temperature is expected to be minus 26 degrees Celcius.  But after officials held an emergency preparations news conference on Sunday to warn everyone to stay inside, the Chicago Teachers Union demanded that officials take the “well-being of the children and teachers” in account and officials relented.