The amazing story of a 16-year-old California boy who the FBI says survived a 5 1/2-hour flight in the frigid wheel well of a jet that flew from San Jose to Hawaii on Sunday raises a logical question:

How does one survive a trip like that when the temperature would have dropped to more than 50 degrees below zero and the air would have been thinner than that at the top of Mount Everest?

Well, as it turns out there have been cases of such survival before, and there's a theory about why the stowaways lived.

Update at 11:33 p.m. EDT: The AP is now saying the boy is 15, not 16, as was earlier reported.

Our original report continues:

The San Jose Mercury News points out that "the last known person to survive as a stowaway in a flight that long was Fidel Maruhi, who in 2000 also hitched a ride in a wheel well from Tahiti to Los Angeles, a seven-plus-hour and 4,000-mile trip where the temperature dropped to nearly minus-50 degrees Fahrenheit."

There have also been cases of stowaway survival on flights from Havana to Madrid and Bogota to Miami.

The Federal Aviation Administration has studied the incidents and concluded that:

"Despite the lack of pressurization, or personal O2 equipment, the presence of warm hydraulic lines in the wheel-well and the initially warm tires provided significant heat."The stable climb of the aircraft enabled hypoxia to lead to gradual unconsciousness. As the wheel-well environment slowly cooled, hypothermia accompanies the deep hypoxia, preserving nervous system viability."With descent, and warming, along with increasing atmospheric oxygen pressure, hypoxia and hypothermia slowly resolved. At the ramp, individuals were found in a semi-conscious state, and, upon treatment, recovered."

The evidence about losing consciousness matches up with what the FBI is saying about Sunday's stowaway, who has not been identified. "He was unconscious for the lion's share of the flight," spokesman Tom Simon told The Associated Press. The flight to Hawaii topped out at around 38,000 feet above sea level.

Stories of amazing recoveries after being frozen, while uncommon, are not unheard of. LiveScience.com recalls that "in the winter of 2001, the body temperature of Canadian toddler Erica Norby plunged to 61 degrees Fahrenheit (16 degrees Celsius) as she lay for hours in below-freezing weather after wandering outside wearing only a diaper. Apparently dead, she recovered completely after being re-warmed and resuscitated." It's thought that if someone is first deprived of oxygen, he goes into something of a "forced hibernation" that slows all biological processes.

We should note, of course, that flying in the wheel well of a Boeing 767 or any other jet is not a safe thing to do.

Not only are you likely to either freeze to death or die from a lack of oxygen, but there's a good chance of plunging from the plane when the landing gear goes down. The AP reminds us about "a man who fell onto a suburban London street as a flight from Angola descended in 2012."

According to USA Today, "there were 95 attempted stowaways on 84 flights around the world from 1996 to August 2012, the FAA says. More than 75% of those attempts resulted in deaths."

Though there have been cases of survival and the FBI is reporting that the California teen says he was in the wheel well during the Hawaiian Airlines flight to Maui, some experts aren't buying the story.

"Somebody surviving at 35,000 feet for five hours with no supplemental oxygen supply — I just don't believe it," ABC News aviation consultant John Nance said on Good Morning America.

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