Bill Nye Faints While Giving Talk: What Made "Science Guy" Collapse?

(CBS/AP) Hyperkinetic science guru Bill Nye collapsed while giving a speech in California, and then got up and continued his presentation.

Nye, 54, host of the the 1990s TV show "Bill Nye the Science Guy," apparently fainted on stage Tuesday evening in front of hundreds of people gathered at the University of Southern California, according to the Los Angeles Times. Paramedics and campus safety officers responded, but it's unclear if Nye was treated.

USC senior Tristan Camacho says Nye collapsed in mid-sentence at the podium. About 10 seconds later, she says he was conscious and asked the audience how long he was out. Nye told the audience a similar thing happened to him earlier in the day.

Nye assistant Christine Sposari didn't immediately respond to an e-mail request for information sent early Wednesday.

What's the science behind fainting?

"Fainting is virtually always a matter of lack of blood flow to the brain," says Dr. David Newman, associate professor of emergency medicine at Mt. Sinai School of Medicine in New York City. "In the great majority of cases the cause remains a bit of a mystery and the fainter recovers without any problem and has no major health problem. Nye woke up and finished his talk, which is certainly a good sign."

Nye's explanation will have to wait.