A woman who died during a water therapy session near the Peak District probably suffered “sudden cardiac death” caused by the cold water, an inquest has heard. Kellie Jean Poole had an undiagnosed heart condition that was likely to have contributed to her death shortly after she entered the River Goyt in Whaley Bridge, Derbyshire, on 25 April 2022. A staff member carried out CPR on the 39-year-old, from Droylsden in Tameside, Greater Manchester, but she was pronounced dead at the scene by paramedics. At an inquest into her death, which began on Tuesday at Chesterfield coroners court, a doctor said the temperature of the water – recorded as 10.7C – was relevant. When asked if the cold water could have caused Poole’s heart to stop, Dr Damian Kelly, a consultant cardiologist, said: “Yes, I think that is what has happened. It is difficult not to see it as relevant.” A postmortem examination, carried out by the consultant pathologist Dr Abed Zaitoun, recorded her cause of death as sudden cardiac death, caused by left ventricular hypertrophy, a thickening of the walls of the lower left heart chamber. Giving his evidence, Dr Zaitoun said Poole was obese according to her body mass index, and her heart was heavier than expected, which could have contributed to her death. Dr Zaitoun said he could not be certain that cold water had caused the sudden cardiac event, as this would change based on temperature and how familiar a person was with being in cold water, but agreed it could have contributed. Cold water therapy has become increasingly popular in recent years, including from among celebritities, with advocates claiming it can treat a number of health conditions, such as inflammation, cardiovascular disease and depression, though not much research has yet been carried out into its effectiveness. The immersion session was booked by Poole’s friend, Victoria Fielding, and was run by a company named Breatheolution led by Kevin O’Neill. Giving evidence, Fielding said it was a “mild” day but that the group were “shivering” prior to entering the water due to being in bathing suits. She said she, Poole and another friend completed about 15 minutes of breathing exercises before entering the water. She said: “He (O’Neill) went up to each of us individually and asked if we had any medical conditions.” Fielding said that Poole appeared to be enjoying the session and was laughing and giggling, but later complained she had a ache in the front of her head. In her statement, Fielding said Poole then fell forward into the water and O’Neill then began performing CPR. The inquest continues.