A stranger carried out resuscitation on a man for 25 minutes after he collapsed in a park – and saved his life.

Now the "incredible" act has spurred Ian Southby's family into learning life-saving techniques.

They want to be ready in case they, one day, can help someone else.

Mr Southby, 65, a fit, and healthy retired fireman, was with his three young grandchildren when he collapsed.

A passing dog walker, heard cries for help and, even though she had never carried out CPR before, did what she could to save him the best chance of survival.

Undoubtedly, she saved his life, and this week Mr Southby's daughter, Nicola Shooter, and daughter-in-law, Louise Wills, were among a group at Thames-side Fire Station, Northfleet, learning how to administer CPR and deal with an emergency as part of Kent Fire and Rescue’s Restart a Heart campaign.

Of the woman who saved her father, Miss Shooter said: “The fact she had no training and still kept going was incredible.”

It took seven days on life support and 13 weeks in hospital before Ian Southby was well enough to return home.

Three months earlier the fit and healthy retired fireman would have been far from the typical victim of a heart attack.

The 65-year-old, from New Barn, did not drink or smoke and had no pre-existing conditions when he collapsed while in a park in front of three of his young grandchildren during the Easter holidays.

Thanks to the actions of the life-saving dog walker, a woman believed to be in her 50s, he is on his way to a full recovery, but the events of April go to show this can happen to anyone anywhere.

The Kent Fire and Rescue Service-led session came at the end of the week-long Restart a Heart campaign which seeks to educate people about how to administer CPR and what to do in an emergency.

Miss Shooter said: “We’ve been wanting to do something like this ever since it happened.”

Just one in 10 people survive a cardiac arrest and the campaign is hoping to increase those odds by educating people, with a particular focus on children.

One of the overriding messages to come from the demonstrations is the simplicity of the process – while non-stop chest compressions for 25 minutes is no small feat the movement itself is simple enough and 999 call handlers talk you through the procedure.

Miss Shooter said: “It’s showed just how exhausting it is to do the chest compressions.

"The fact she kept going for almost half an hour and was only a little lady was phenomenal.

"She was absolutely amazing and the fact she had no training and still kept going was incredible.”

• Do you know the life-saving woman? Contact our Gravesend newsdesk on 01474 564327.