LOS ANGELES - The 12-year-old boy who was rescued after spending 20 minutes in the cold Pacific likely survived because of his age, among other factors, experts say.

Dale Ostrander was visiting the southwest Washington coast with his church youth group last Friday when he was swept out by a riptide. Rescuers who pulled him out said he had no pulse and his face was pale.

So how did he survive?

Studies of near-drownings in cold water have found that survival depends on many factors including a person's age, water temperature, time spent underwater and how fast CPR is given.

"He's young and healthy," said Dr. Mark Morocco, an emergency room doctor at the Ronald Reagan UCLA Medical Center in Los Angeles. "Your chances of surviving are better if you're young."

After people get over the initial shock of being plunged into cold water, they generally can survive for a certain period before getting exhausted or falling unconscious.

According to the National Weather Service, the water temperature at the time was around 13 C. People generally can survive in that water temperature for about half an hour before their muscles get weak and they lose strength. There's also risk of hypothermia, which occurs when the body loses heat faster than it can produce it, leading to a dangerously low body temperature.

Kids tend to be more resilient than adults. Scientists point to an innate response that is triggered when people are plunged into cold water. The heart rate slows down and blood is diverted to the brain and other core organs. This so-called diving reflex is more pronounced in children, allowing them to better survive in frigid water. It's unclear how much this might have played a role in Ostrander's case.

Morocco said it doesn't appear the boy was underwater the entire time based on witness accounts.

"He probably was still breathing regular air and not water" for part of the time," Morocco said.

Swift treatment also helped. Morocco credited the rescuers for continuing resuscitation efforts even though Ostrander had no pulse and appeared dead.

"This is a perfect golden hour case," he said, referring to a brief window in medicine in which lives can be saved with prompt treatment.

In 1975, an 18-year-old was underwater for 38 minutes after driving off the road and into an ice-covered pond in Michigan. Paramedics initially thought he was dead, but the man eventually woke up 13 hours later in a hospital. Morocco said medical literature cites at least one case in which a person survived after being submerged for up to an hour.

It's unclear how long Ostrander was underwater, but based on witness and rescuer accounts, it could have been 20 minutes.

"Whether or not it was a miracle depends on the details," said Dr. Paul Auerbach, who teaches emergency medicine at Stanford School of Medicine.