"On the set of 'Morning Joe' this morning, Tom Brokaw felt light-headed," NBC News President Steve Capus said in a statement. "Out of an abundance of caution, he was taken to a hospital. He is being evaluated, is in good spirits, and is expected to be released shortly."

Brokaw, 72, whose title now is special correspondent, was in Charlotte for the Democratic National Convention.

"All is well Early AM I mistakenly took a half dose of Ambien and made less sense than usual," Brokaw said on his official Twitter feed, @tombrokaw.

"Made a better comeback than Giants," Brokaw's tweet continued, referring to Wednesday night's 24-17 loss by the New York Giants to the Dallas Cowboys in the opening game of the National Football League's 2012 regular season.

Brokaw served as anchor of NBC Nightly News for more than two decades, stepping down from that post in December 2004. He has remained affiliated with NBC, pursuing enterprise reporting projects as a special correspondent.

Brokaw is also an author of several books, including the best-seller, "The Greatest Generation," his telling of the history of the U.S. generation that grew up in the Great Depression and fought World War Two.

(Reporting By Dan Burns; Editing by Vicki Allen)

• A Permanent Economic Emergency