Police officers saved a man's life after he collapsed with a heart attack in sweltering heat - while being verbally abused by a watching crowd.

Three constables rushed to revive the man, in his 50s, and kept him alive with CPR until paramedics arrived on the hottest July day on record.

In shocking scenes, passers-by who gathered to watch interfered and heckled as the officers' battled to save his life in West Croydon, police said today.

The man, who collapsed in London Road at about 11.30am on Wednesday, is thought to have suffered an epileptic fit that triggered the heart attack.

Paramedics and doctors at Croydon University Hospital, where he was taken, said the quick response of PCs Michael Dobson, Michael Jones and Jordan Harwood-Lewis had saved his life.

They also received praise from Croydon police's borough commander, Chief Supt Andy Tarrant, for their "outstanding work in what were extremely difficult circumstances".

PC Dobson was on patrol on Wednesday, a day in which temperatures soared to 36C in London, when he received a call about the man's collapse.

He moved the man into the recovery position, called an ambulance and attempted to rouse him by talking to him. 

PCs Jones and Harwood-Lewis then arrived, but the man suddenly stopped breathing. They performed CPR for ten minutes until an ambulance crew arrived.

The man has since regained consciousness in hospital.

Chief Supt Tarrant said: "This was outstanding work in what were extremely difficult circumstances, compounded by the extreme heat.

"Even with a volatile crowd the officers managed to keep their resolve and continue administering first aid to an excellent standard, resulting in the man's life being saved.

"The officers should be very proud of themselves, displaying outstanding professionalism and acting in the best traditions of the Met Police."

Wednesday was London Ambulance Service's busiest summer day in history, with paramedics dispatched 1,571 life-threatening incidents - a quarter more than the previous Wednesday.