A much-loved teacher from Newcastle upon Tyne died on a family day out to a waterfall to celebrate his 36th birthday when he went into shock after jumping into the water, an inquest has heard.
Wadud Abdul was with his wife, Cheryl, and their two children, Mya, 13, and Isa, 22 months, enjoying a picnic at Low Force beauty spot near Middleton-in-Teesdale, County Durham, when he leapt into the river on a pleasant May afternoon.
He did not resurface and after a major search by the emergency services his body was recovered the next day from the bottom of the pool below the waterfall.
Pathologist Dr Sree Mussunoor told an inquest in Crook, County Durham, that sudden immersion in cold water can cause a spasm which stops the heart from beating.
Coroner Andrew Tweddle asked how much time there would be for a rescuer to bring someone back from the shock.
Dr Mussunoor replied: "Usually in these circumstances death ensues within a couple of minutes. It is a very short window."
He agreed with the coroner's suggestion that unless the stricken swimmer has someone close by to pull them immediately from the water and then perform CPR, there was little hope of saving them.
Inspector Andy Reeves said police officers and the force helicopter, fire crews and mountain rescue teams were called to the scene at around 3.30pm on May 28th - the school teacher's 36th birthday.
Searchers in boats and canoes and officers using ropes scoured the river looking for Mr Abdul, without success.
It was not until the next day, when the water flow coming from a reservoir upstream was slowed, that his body was recovered by specialist divers close to the base of the waterfall.
Mr Reeves said:"This was just a normal family day out."
Coroner Mr Tweddle said: "This was not a case where there was any daftness or silliness going on - sometimes you hear of examples of misbehaving, there was nothing like that.
"It was a family day out and, unfortunately, as Dr Mussunoor said, there can be a random and unpredictable response to the body when it gets immersed in cold water."
He said the only conclusion was that Mr Abdul died as a result of an accident.
After the hearing the teacher's widow thanked the emergency services for their efforts.
"I really hope that people can learn from this and prevent it from happening again," she said.
"We would still have him if we had known the dangers of cold water."
Mr Abdul had three brothers and three sisters, and his parents and two of his brothers also attended the inquest.
After the hearing, Mr Reeves said: "I would like to remind people of the dangers of cold water shock that can affect anybody, no matter how healthy they are. The water can look nice but there are dangers lurking underneath."
Mr Abdul worked at the school for 10 years and pupils held a candlelit assembly in his memory after they were told of his death.