• CHICAGO (AP) -- Much of the country continued to grapple Tuesday with a historic freeze that shuttered schools and businesses at the start of the first full work week of 2014. Flights, trains and bus transportation were disrupted, thousands were left without power and even parts of the country used to fending off hypothermia and frostbite had to take extra precautions as temperatures and wind chills approached record levels.
• Here are five things to know about the deep freeze, as well as a photo gallery highlighting how people in the Midwest and elsewhere were dealing with the polar vortex.
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• . COLD OUTSIDE? YOU'RE NOT ALONE
• Nearly 187 million people, more than half of the nation's population, were under a wind chill warning or advisory.
• The winds made it feel like 55 below zero at one point Monday in International Falls, Minn., and parts of the Midwest accustomed to temperatures that are cold -- albeit seldom this cold.
• But even the coal fields of Virginia and West Virginia had a wind chill of negative 35.
• Every major weather-reporting station in Minnesota, North Dakota and Wisconsin noted temperatures below zero at 11 a.m. Monday, and South Dakota would have joined them if not for the 1-degree reading at Rapid City.
• The coldest temperature reported in a 24-hour period through Monday was -36 degrees at Crane Lake, Minn. The warmest: 84 in Hollywood and Punta Gorda, Fla.
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• . FLY AWAY FROM THE WEATHER? THINK AGAIN
• More than 3,700 flights -- around one out of every 10 domestic departures -- were canceled by Monday afternoon, following a weekend of travel disruption across the country. The bulk of those cancellations were in Chicago, Cleveland, New York and Boston.
• "It's been one weather system after another," said Delta Air Lines spokesman Morgan Durrant. "It's been a challenging 72 hours."
• With wind chills as low as 45 below zero at some airports, workers could remain exposed on the ramp for only a few minutes. That made loading and unloading lug

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