NEW YORK – From the Rocky Mountains to New England, hospitals are swamped with people with flu symptoms. Some medical centers have limited visitors, and one Pennsylvania hospital set up a tent outside its ER to handle the feverish patients.

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.

"Those of us with gray hair have seen worse," said Dr. William Schaffner, a flu expert at Vanderbilt University in Nashville.