Blue alert as mercury hits minus 50 C

A resident watches ice cascade outside a building in Yakeshi city of Hulunbuir, North China's Inner Mongolia autonomous region, Feb 5, 2012. Temperatures in Hulunbuir plummeted to minus 50.7 Celsius after a cold front hit the city last Friday. The National Meteorological Center issued a blue alert on Monday, the lowest level in the country's four-scale alert system. [Photo/Asianewsphoto]