<div>In the US Midwest, more than 1,000 flights were canceled at two airports in Chicago, America's third largest city, due to a major snowstorm.</div>''<div><br />''</div>Nearly a dozen states braced for a blast of arctic air known as a polar vortex, which was expected to lower temperatures far below zero.  National Weather Service yesterday said  that dangerously cold  temperatures and wind chills are expected today and tomorrow.<br />''    <br />''In Minnesota and Wisconsin schools, universities, government offices,  and businesses remained shut with the mercury expected to drop to a polar – 40 Celsius.  In Minnesota, numerous cities declared snow emergencies, local media reported.   In Wisconsin, Governor Tony Evers declared a state of emergency, freeing up the Wisconsin National Guard for emergency work, if needed. <br />''<br />