article_snippet.sent: The 19-year-old, named locally as Moses Yitzchok Greenfeld (above) from Stamford hill, London, was pulled from the water in Hampstead Heath, north London, after getting into difficulty while swimming .
article_snippet.sent: It is thought Mr Greenfield may have had a cardiac arrest because of the shock of jumping into the cold water.
article_snippet.sent: It is believed Mr Greenfeld may have suffered a heart attack brought on by the sudden change in body temperature after diving into the chilly 8C  pond, the Evening Standard reported.
article_snippet.sent: Andrew Dutton-Parish, a regular swimmer at the Men's Pond who was also at the heath, added: 'It's such a sad start to the summer.
article_snippet.sent: The teenager is the second person to have died while swimming on the heath in the past two years.
article_snippet.sent: In August 2013, photographer Sussie Ahlburg, 51, from Holborn, drowned in the pond.
highlights_snippet.sent: Moses Yitzchok Greenfeld died while swimming in Hampstead .
  
highlights_snippet.sent: Moses Yitzchok Greenfeld was seen in difficulty in water at 5.30pm and body recovered at 11pm .
  