The National Weather Service (NWS) warned of an Arctic air blast from Canada continuing to provide subzero temperatures for the U.S. Midwest, Southeast, Mid-Atlantic and Northeast on Wednesday evening and into Thursday. On Wednesday, public school officials in Chicago, Milwaukee and Boston canceled Thursday classes out of caution, saying the frigid temperatures in the forecast pose a danger to children. “Our top priority remains the safety of our students, and tomorrow’s weather conditions could again be dangerous to students traveling to and from school,” said Chicago Public Schools CEO Barbara Byrd-Bennett in a statement to parents. Chicago Public Schools, the third-largest U.S. school district with 400,000 students and almost 800 schools, told students on Wednesday to stay home and indoors as temperatures dropped to between 20 and 30 degrees Fahrenheit below average. Overnight readings were expected to be as low as 16 below zero. There was little snow-day fun for children freed from school. Sledding hills and cross-country ski areas were shut down around Chicago, and in South Dakota, the city of Sioux Falls closed six ice-skating rinks, citing wind chill peril. Pat Powers, 48, of Brookings, S.D., about 50 miles north of Sioux Falls, put on snow gear to go shopping for sugar to take home for his teenaged daughter who wanted to bake on her day off from classes. He said he preferred to run the errand rather than let her out in the cold. “It’s a good day to stay home and blog in your pajamas,” said Powers, a political blogger. Although Chicago was sunny and clear, commuters said uncovered hands and faces became painful after a few seconds in the brutal cold. The National Weather Service warned that frostbite could happen with just 15 minutes of exposure and advised people to keep pets indoors. Chicago’s trains and buses were less crowded than normal as some workers stayed home. There also were some delays of buses and trains due to the weather. The NWS issued wind chill alerts for cities including Chicago and Detroit as strong Arctic high pressure built into the Midwest. Overnight wind chill values could reach 25 to 35 degrees Fahrenheit below zero, the weather service said. “Dangerously cold wind chills will continue Thursday morning,” in northern Illinois and northwest Indiana, the weather service said. BLIZZARD-LIKE BLOWING SNOW  The weather service forecast blizzard conditions for parts of South Dakota on Thursday afternoon because of blowing snow, not fresh snow. All Sioux Falls public and parochial schools were shut on Wednesday. Atmospheric pressure hit possible record highs in Aberdeen, S.D., the NWS said. High barometric pressure is associated with cold air from the polar regions. In Chicago, parents scrambled to line up child care after schools closed. Kim Dooley, 52, was on the elevated train into work after rushing to find a nanny for her 6-year-old special-needs daughter. “People aren’t as hardy as they used to be,” she said. In Minneapolis, where the temperature was 8 degrees below zero Fahrenheit, commuters left their parka hoods up inside  trains and pedestrians walked with their hands over their faces. Most Midwesterners took the cold in stride and said the temperatures seemed normal compared to last year’s polar vortex storms. “This is nothing. It does not compare to any of the epic storms that we’ve had,” said businessman Matt Minar, 42. Ohio saw snowfall overnight but nothing unseasonable. “This time last year was worse,” said Steve Carlson, 49, a Cleveland native and customer service worker for AT&T who had calls scheduled for outdoor work all day. Farther south, outdoor workers in Kentucky doubled up on coats to protect against wind chill temperatures of 4 degrees below zero. “I drink a lot of hot chocolate,” said Eddie Rainbolt, 50, in Louisville, a sign holder for Solid Gold, which buys gold and silver. Several Southeastern states also braced for frigid cold. In Atlanta, the medical examiner’s office said it was investigating the death of a man found outside a bus stop that may have been weather-related.
'Baby, It's Cold Outside': large part of U.S. in deep freeze.