Visitors take pictures overlooking the falls in Niagara Falls, Ontario, January 8, 2014. The frigid air and "polar vortex" that affected about 240 million people in the United States and southern Canada will depart during the second half of this week, and a far-reaching January thaw will begin, according to AccuWeather.com. REUTERS/Aaron Harris (CANADA - Tags: ENVIRONMENT TRAVEL)
Organic farmer Will Muir of Wholesome Living Farm breaks through the ice on a pond so his cows can access drinking water in the midst of bitter cold below-zero temperatures on January 7, 2014 in Winchester, Kentucky. Temperatures in the single digits coupled with below-zero wind chills have prompted the closure of local governments, schools, and businesses throughout the South. Luke Sharrett/Getty Images/AFP