http://www.cnn.com/2009/HEALTH/10/16/cheating.near.death/index.html

(various doctors speak about the reality of near death experiences and some different situations under which they can occur)

from the article:

"...Bob Schriever, co-founder of the Sudden Cardiac Arrest Association, was refereeing a high school football game seven years ago when he went into cardiac arrest, died and was revived.

He, too, questions the dream explanation. "Why are so many people dreaming the same thing? How can so many people, and there's hundreds of thousands of people who have experienced this, how can we all be dreaming the same thing and describe the exact same thing?"