The East Anglian Air Ambulance was called to a man who collapsed in Maynewater Lane, Bury St Edmunds.
Paramedics were called at 9.10am to the man, aged in his 60s, who suffered a cardiac arrest, was unconscious and not breathing.
A spokesman for the East of England Ambulance Service said they sent two ambulances, an officer and a response car.
There was also the air ambulance and a doctor from the Suffolk Accident Rescue Service.
He said: “Following treatment at the scene, they managed to get his heart beating again and they took him to West Suffolk Hospital in a critical condition by land ambulance.”