A 66-year-old walker was airlifted to hospital after suffering a cardiac arrest while out on the fells.
Keswick Mountain Rescue Team was called out at 1.50pm on Saturday.
The man, who was out walking with a group, was taken ill on Blease Fell. Fellow walkers phoned for assistance immediately.
Within minutes the Pride of Cumbria air ambulance was at the scene.
Members of RAF Leeming Mountain Rescue Team, who were in the area, also offered their assistance.
The air ambulance were able to land close to the casualty, and the Keswick team were on scene when the casualty suffered a cardiac arrest.
The air ambulance medical team used a defibrillator to restart his heart, and the mountain rescue volunteers stretchered him quickly to the aircraft.
He was flown to the Cumberland Infirmary for specialist treatment.
The Keswick team said had the man's companions not been as alert, the consequences could have been much more serious.
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