Extreme cold and record-low temperatures are sweeping through parts of the United States, especially the Midwest.<br />For more on this and other news around the world we turn to our Ro Aram…<br />Aram… we are having a mild winter here in Korea,... but it's literally the polar opposite in the U.S....<br /><br />That's right, Mark… Weather authorities are warning this cold wave could be life-threatening. <br />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 United States.<br />The Midwest will be hardest hit, experiencing temperatures not seen in a quarter century.<br />The Chicago area and northern Illinois are forecast to see the mercury dip to almost minus 50 degrees Celsius - temperatures usually found in the Arctic Circle.<br />The mercury in other areas will hover around minus 20.<br />Bone-freezing wind chills will be accompanied by heavy snow, with as much as 60 centimeters expected in Wisconsin.<br />Schools in several cities have been closed and hundreds of flights have also been cancelled. <br />People are being advised to stay indoors as those outside in the intense could experience frostbite within 10 minutes.<br />Dozens of warming centers have also been set up. <br />Temperatures were expected to be at their coldest on Wednesday. <br />
