You may have read in some of the newspapers about a woman who survived after her heart stopped beating for six hours. Students have been taught that if you try to start the heart 4 minutes after it had stopped beating, the patient will most probably be brain dead. This patient had a fully functioning brain after 6 hours. This report illustrates the power of Hypothermia in preserving life.

Read the Report: A British teacher in Spain whose heart stopped beating for more than six hours was revived in a case that doctors said was “exceptional in the world”.

Audrey Schoeman, 34, was brought back to life after suffering cardiac arrest induced by hypothermia on November 3 when she was caught in a Pyrenees snowstorm with her husband, Rohan.

She was rescued, flown to Vall d’Hebron hospital in Barcelona and survived thanks to close co-ordination between rescuers and medical staff.

“It is an exceptional case in the world; the longest cardiac arrest documented in Spain,” Eduard Argudo, the doctor who led the hospital’s operation to save her life, said during a press conference with Mrs Schoeman yesterday. “There are almost no cases of people whose hearts have stopped for so long and have been able to survive.”

Mrs Schoeman, who teaches English in Barcelona, does not remember the rescue but thanked the emergency services and medical staff “who did more than is normal to save me”.

“I didn’t realise that my life was in danger until I woke up here,” said Mrs Schoeman, who left hospital 11 days after being rescued. “It’s amazing that I survived. I am happy,” she added. “The care has been fantastic. The more I learn and read about it, the more miraculous it seems that I have survived.”

Her husband realised she had hypothermia when she “began to say strange things”. Lost in the mountains, taking refuge from a snow storm behind a rock “the size of a chair”, Mr Schoeman tried to summon help. By the time the storm passed and he could get a signal, Mrs Schoeman was showing no vital signs.

Mr Schoeman put calls through and sent photographs of their location in the Vall de Núria to friends and waited. Two hours later, at 3.30pm on November 3, a rescue helicopter managed to locate the keen hikers. Suffering from severe hypothermia, Mrs Schoeman’s heart was no longer beating.

Medical teams began to perform cardiopulmonary resuscitation. In view of her condition, they decided to transfer her to Barcelona, where she arrived at 5.45pm.

“She was pale and blue, with a body temperature of 20C,” said Dr Argudo. “The only good thing was that she was very cold. Everything else looked very bad.”

Normal body temperature is 37C. Cold lowers the need for oxygen and nutrients in the cells and allows the body to last longer while undergoing resuscitation, the doctor explained. Mrs Schoeman’s heart had no electrical activity and her kidneys and lungs were not functioning.

Doctors gave her extracorporeal membrane oxygenation treatment (ECMO) that supplements the function of the heart and lungs, extracting blood which is then oxygenated outside the body before it is reintroduced through an artery. The ECMO machine also heats the blood, allowing the body temperature to rise gradually.

When her body reached 30C, the doctors used a defibrillator to revive her. Her heart started beating at 9.46pm, more than six hours after it had stopped, but she was kept in a mild state of hypothermia to prevent brain damage.

“We were especially concerned about the possible neurological effects,” said Dr Argudo, “since there are practically no cases of people having been revived after having their heart stopped for so long.”

Mrs Schoeman needed several blood transfusions and was heavily sedated for 48 hours while she remained in the chilled state. Three days later she was conscious and able to talk, and left the hospital 11 days after being rescued.

She said yesterday that her hands were still damaged. “There are many things I can’t do, like doing up the buttons of my trousers and putting on my earrings, which my husband helps me with, but these are very small things that are going to improve month by month.”

Ms Schoeman hopes to return to the mountains within a year. “Maybe we weren’t as prepared as we should be, we were reckless,” she said. But she added: “I don’t want this to take away this hobby from me.”

Surgeons in Siberia in the 1960s did not have cutting edge treatments. When they needed to perform heart surgery, they could not rely on the technology. But there is one resource they had in abundance: cold (Tom Whipple writes).

So when Eugene Meshalkin knew he had a difficult operation ahead, he would pack his patients in snow and ice beforehand, and watch their bodies slow down.

A stopped heart kills you first because it deprives your brain of oxygen. There are two ways to deal with that. The first is to get the blood flowing again — using a heart bypass machine so you can operate unimpeded. The second, the one employed by Professor Meshalkin, is to chill the body and its cells so that they last longer without oxygen.

This is also the technique that, by accident, saved the life of Audrey Schoeman. Hers is one of a smattering of such cases through history.

Most famous was in 1999, when a Swedish skier who fell under ice spent more than an hour submerged, then was revived. In the Napoleonic wars, and the frozen march on Moscow, a surgeon was intrigued to notice that wounded officers often recovered less well than infantry — concluding it was because the former were placed close to the fires.

Done right, the results of therapeutic hypothermia can be stunning — extending the time brains can survive without oxygen from minutes to over an hour.

Although bypass machines are now used routinely, the work of Professor Mashalkin and those who followed has not been forgotten. Patients are still sometimes chilled before surgery.

Last month, doctors in the US announced that they had gone further. For the first time they deliberately put a trauma patient into “suspended animation”, replacing his blood with chilled saline solution to give doctors longer to save him.

Mrs Schoeman effectively received the same treatment, just administered by nature.

Report by Isambard Wilkinson from Madrid for The Times