Swimmer Dies in 10-K Race: What Really Killed Fran Crippen?

(CBS/AP) Can hot water and hard work kill an elite athlete?

That's the question being put before race officials in the United Arab Emirates who are being asked tough questions about the racing death of U.S. national team swimmer Fran Crippen.

The 26-year-old died Saturday while finishing the final leg of the Open Water 10-kilometer World Cup off the coast of Dubai.

He "exerted himself more than he could, that's what we know," said Julio Maglione, president of FINA, the body that oversaw the race.

The race winner, Thomas Lurz of Germany, had another idea. He said the water was too hot to race and the schedule too grueling.

Does either theory hold water?

Officially, the water temperature on race day was 84 degrees, though Lurz said it felt closer to 86. He also said several other swimmers complained of swollen fingers and toes and some became confused following their race. Three were hospitalized.

Confusion is a sign of the brain being overheated, experts tell CBS News. But was that enough to kill Crippen?

Surprisingly, there is little research on the effects of hot water on athletes.

Swimmers produce just as much body heat when they race as other athletes, and in cold water that heat is easily dispersed, says Dr. Michael Bergeron, an expert on heat and hydration issues. But in warm water the heat remains trapped in the body, he tells CBS News.

Scientists know a lot about the upper limits for swimming in cold water, as well as for bathing in hot tubs and saunas. But when it comes to exerting one's body in warm water, there's a big question mark says Bergeron, who serves as director of the National Institute for Athletic Health and Performance at Sanford Health in Sioux Falls, S.D.

Crippen was at the top of his game when he died. In August, he took silver at a similar event in California and finished fourth in this year's championships for the event.

Crippen's body was found 400 meters from the finish line by fellow swimmers. Ironically, he had complained about inadequate safety precautions shortly before his death - a call that went unanswered.

Results from an autopsy are pending.