Dr. Meeta Khan wears a face mask as she examines a respiratory patient at the Rush University Hospital emergency department, Thursday, Jan. 10, 2013, in Chicago. Flu season in the U.S. has hit early and, in some places, hard. But whether this will be considered a bad season by the time it has run its course in the spring remains to be seen. (AP Photo/Charles Rex Arbogast) Photo: Charles Rex Arbogast