The chances of saving Tracey Patterson and the two men who tried to rescue her were always remote. But the fact that the water into which they plunged was freezing cold did provide a glimmer of hope.
Doctors at Pontefract General Hospital, West Yorkshire, knew that it takes longer to drown in freezing water than warm water and it is possible for someone to remain unconscious for up to half an hour with little oxygen.
Dr Kenneth Collins, an expert on hypothermia at University College Hospital, London, explained: "You become so cold that your tissues do not need so much oxygen. The heart rate also slows down, so the heart does not have to work so hard to pump blood round the body. It usually takes a person up to five minutes to drown as the result of no oxygen in average river or sea water temperature, but the process is prolonged once you are in freezing water."
Children are more likely to survive in freezing water owing to a phenomenon known as the "diving reflex", which is similar to a reaction in ducks and certain birds searching for food in freezing water. As the sensitive muscle areas surrounding the beak or bill are plunged into freezing water, it causes a reflex action which slows down the heart and breathing, resulting in less oxygen being used.
Nigel Wylie, Wakefield operations director for the West Yorkshire Ambulance Service, said: "Because of the freezing temperatures, it almost puts the body into a state of suspended animation, it slows the body down to such a degree it doesn't need the same oxygen and other things to sustain human life.
"There have been cases where people have survived cold water drowning, but I do not know how much that could have applied in this case. I have not come across a case where people were immersed in freezing water for so long."
"We were incredibly lucky that the police underwater team found them in the time they did for a lake of such size, and got them to the hospital to at least afford them the opportunity of resuscitation."
At Pontefract, three teams, each five strong, worked on Tracey and on Michael Mee and Jack Crawshaw - the men who attempted to rescue her - by trying to raise their body temperatures slowly.
Their hearts were massaged to maintain their blood flow and ventilators artificially maintained their breathing as their temperatures rose. Warm fluids were pumped into their internal cavities to heat their internal organs and blood. Special blankets prevented further heat loss from the skin and warm air was blown over the limbs.
Mike Playforth, the hospital's accident and emergency consultant, said the teams had managed to raise the three victims' body temperatures to the critical level of 32C, five degrees below normal body temperature. "The core temperature was achieved and at that time we were able to attempt normal resuscitation techniques.
"The expectation was for the heart to begin fibrillation, but we had no indication of any electrical activity in any of the patients."Reuse content