Freezing "to death" saved Justin Smith's life.

The 25-year-old Pennsylvania man doesn't remember much after leaving a bar on an icy night last year –and wasn't conscious when his father found him the next day lying in the snow on the side of the road with no pulse.

Paramedics responding to the call thought Justin was dead. He'd spent 12 hours outside with temperatures that plunged to five below zero.

A coroner was already on the way, but Dr. Gerald Coleman, who was in contact with the first responders told them to start CPR.

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Coleman knew if a person freezes slowly, at just the right speed, it lowers metabolism through the body. This means the person won't always suffer the other effects of exposure that can destroy the brain and other organs. The freezing temperatures can actually keep people alive and, in some cases with the right medical care, those people can make a full recovery.

Justin was one of the lucky ones — and a record-setting one. Coleman says with his upper body actually frozen solid when he was found, Justin is the coldest person to have ever lived through hypothermia caused by exposure.

They hooked him up to an extracorporeal membrane oxygenation — or ECMO — machine. A frozen person's blood is pumped into the ECMO which warms and restores oxygen to it, before pumping it back into the patient.

Later in the day, Justin's heart started beating on its own.

Now, one year later, Justin took time off from college to return to the hospital to publicly thank Dr. Coleman and everyone else who saved his life.

"I consider my life a miracle," he told the people who made that "miracle" happen.

(WATCH the video below from the Lehigh Valley Health Network and SEE more, w/ photos at CBS News) — Photo: Lehigh Valley Health Network video

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