In the winter of 1981, teenager Jean Hilliard was on her way home at around midnight when the family car she was driving ran off the road near Lengby, Minnesota. Unable to free the vehicle, she made the dangerous decision to leave the car on foot, and attempt to walk to the nearby home of her friend, Wally Nelson.
Hilliard trudged along in the snow, her cowboy boots slipping occasionally and slowing her progress. She began to grow tired, and was nearly to the point of collapsing by the time she could see the shape of Wally's home off in the distance.
Whether or not Hilliard could make it or not in those final moments may have been far from her mind, but there in the frigid early morning hours, she collapsed into the snow, only 15 feet from Nelson's front door.
The following morning, Wally was leaving his home at approximately 7 am when he saw Hilliard's body in the snow. He quickly lifted her up, and finding her body quite literally "stiff as a board", he loaded her into the back of his car at an angle ("diagonally", as he told reporters after the incident), and hurried her off to the hospital in the nearby town of Fosston, and probably with little hope that she might be revived.
Once Hilliard was admitted to the hospital, doctors found her flesh so frozen that hypodermic needles couldn't puncture her skin. However, almost miraculously, her body had maintained a low pulse throughout the evening, and as Hilliard was admitted to the ICU her heart had been beating at a mere 12 beats a minute, with a body temperature of around 88 degrees. Her caretakers wrapped her in an electric heating pad, and hoped to slowly thaw the frozen girl.
Despite the odds, Hilliard not only revived, but suffered few of the lasting affects many would sustain after such an ordeal, namely that of amputation. ''At worst, I might lose a couple of toes,'' she told the New York Times. Also quoted had been Dr. George Sather, who marveled over her remarkable ability to survive what seemed impossible:
''I can't explain why she's alive,'' Dr. George Sather, who helped treat the young woman, said today. ''She was frozen stiff, literally. It's a miracle.''
Hilliard's case isn't the only remarkable instance where a human being apparently fell into a hibernation-like state in the face of extreme cold. An even more extreme example involved Mitsutaka Uchikoshi, who went missing on October 7, 2006 during a climbing expedition with friends on Mount Rokko in western Japan. As he lay down in a field where sunlight could strike his body, Uchikoshi's temperature dropped to 71 degrees, and he remained there undisturbed for 24 days.
Upon discovery, it might easily have seemed that only remains were left of Uchikoshi; he had almost no pulse, and his organs had nearly entirely shut down, as was reported by BBC News:
Medics say they are still puzzled how he survived because his metabolism was apparently almost at a standstill. Mr Uchikoshi is believed to have tripped and lost consciousness after leaving his party to descend from the mountain on his own.
"I lay down... in a grassy area, which felt good in the sunshine, and eventually I fell asleep," Mr Uchikoshi told reporters at a news conference at a hospital in Kobe, where he was treated. "That's the last thing I remember," he said.
He was found by rescuers on 31 October.
"He fell into a hypothermic state at a very early stage, which is similar to hibernation," said Dr Shinichi Sato, who treated Mr Uchikoshi. "Therefore, his brain functions were protected without being damaged and have now recovered 100%. This is what I believe happened," he said.
Another remarkable case, albeit one which some have viewed somewhat questionably, involved a Swedish man who purportedly survived for two months in sub-zero temperatures by "hibernating" in a car. Peter Skyllberg was said to have had nothing but snow to eat, and comic books to pass the time, and yet the 44-year-old man somehow managed to survive until a snowmobile operator spotted his vehicle, and contacted rescue workers. While his attending doctor suggested Skyllberg's was another case of "human hibernation," others believed he lived because his car had insulated him in much the same way an igloo functions.
In addition to cases like these mentioned, there is some scientific literature that seems to support the idea that humans can hibernate in rare instances, perhaps a latent sort of ability carried over from our animal cousins who still do it. In more recent studies, hydrogen sulfide gas has been used during experiments that succeeded with inducing hibernation states in laboratory mice, who emerged once their source of air was returned to being normal oxygen. It is believed that such techniques could be used in the future to induce hibernation in humans along the same lines, for purposes of things the likes of space travel over long periods.
Knowing that induced states of hibernation can occur doesn't fully explain what allows certain individuals to succeed at doing it naturally; doing so has not only been achieved, but arguably, it also saved the lives of those who managed to do it. Could humans truly possess the ability to enter a hibernation-like sleep in extreme cold, and if so, how might understanding the way it happens be useful in the future?