Updated

Despite the subzero temperatures and lack of oxygen, people can survive even a long journey in the wheel well of a jetliner. The latest example is a teenager who, according to authorities, stowed away on a 5 1/2-hour flight from San Jose, Calif., to Hawaii. While the number of known stowaway attempts is few, people have survived with surprising frequency.

HOW DANGEROUS ARE THE CONDITIONS?

Very. At 38,000 feet — the cruising altitude of the Hawaiian Airlines flight that the FBI says the 16-year-old took Sunday — the outside air temperature is about minus 85 degrees. The air is so thin that a person will pass out when the brain is starved of oxygen.

And then there is the huge risk when the wheels are lowered for landing. This opens the equivalent of a trap door, turning a cramped but relatively sheltered space into one from which it would be easy to fall thousands of feet to the ground or water below.

SO HOW CAN THE HUMAN BODY DO IT?

By entering a state akin to hibernation. Breathing, heart rate and brain activity continue but at a much slower-than-normal rate. Being younger helps, though surgeons may try to recreate this body state during open heart surgery on older people.

In addition, the plane's own machinery can aid a stowaway's survival. Heat radiating from the wheels and from hydraulic lines can moderate the temperature, at least initially.

HOW FREQUENTLY DO PEOPLE SURVIVE?

Worldwide, there have been 105 known people who stowed away since 1947, according to data kept by the Federal Aviation Administration. Counting the California teen, 25 made it alive, for a survival rate of about 1 in 4. The FAA notes that the rate may be lower, because people could have stowed away and fallen out of the wheel well without anyone knowing.

Prior to this case, there were two known instances when someone stowed away on a flight that took off and landed within the United States. One was in 2010, in which a teenager died on a flight between Charlotte, N.C., and Boston. The other was in 1972. There are other instances in which someone flew to the United States from another country.

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Contact Justin Pritchard at https://twitter.com/lalanewsman

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Associated Press researcher Rhonda Shafner in New York contributed to this report.