The family of the male casualty who was helped by the air ambulance are appealing to find the kind stranger who rushed to his aid.
On Saturday, May 18, a man suffered a heart attack in the Derwent Road Play Area whilst with his family.
The emergency services were called at 3.38pm and while his loved ones were waiting for the ambulance crews to arrive, a kind female stranger offered to give CPR.
The family, who wish to remain anonymous, said: "Thanks to the heroic actions of a number of people, we are able to confirm that the gentleman is in a serious but stable condition in a specialist hospital.
"We would like to thank all the people in the park and surrounding field who rushed to assist, in particular the lady who promptly started delivering CPR which has given the gentleman and the family hope. The family would like to trace this lady so they can express their gratitude to her.
"We would also like to thank the 999 call handler, ambulance crew, air ambulance crew, local police and all others who assisted for their quick and life saving actions on the day, as well as the hospital as they continue his care, and the local community for their ongoing support."
If you think you can help to find the lady, please contact the Leighton Buzzard Observer who will put you in touch with the family. They are also inviting any witnesses to get in touch if they would like to speak with the family.
A spokesman for Essex & Herts Air Ambulance said: “On May 18 an Essex and Herts Air Ambulance was tasked to assist EEAST and Bedfordshire Constabulary with a male patient medical emergency. Teams worked together on scene to optimise patient outcome. The patient was transferred to a specialist hospital for ongoing treatment.”