A Sheffield dad is championing tracking devices for people with early onset dementia after his own father vanished twice - ending up in London and Scotland.
David Zadeh, aged 27, said he could have lost his dad 'for good' on two occasions after he disappeared without warning and voyaged hundreds of miles from home.
But because his 60-year-old father, who started with early-onset dementia six years ago, carried a tracking device, police managed to find him safely.
David, of Dore, said: "If it wasn't for GPS tracking, we could have lost him for good on two occasions. Anything could have happened to him, it's frightening.
"The issue with early-onset dementia is that people can still be very active, like my dad, and should remain as active as possible. But they are also confused and things like this can happen - even if you take precautions."
David said his father, whom he does not want to name, would typically go walking around his neighbourhood every day, but would always return at the same time.
He said: "One night, around six months ago, my father was half an hour late returning home so we checked the tracking device and saw that he was in London.
"I couldn't believe it, panic set it. Not only that, he had walked from Kings Cross station, right across the city and was found south of the river in quite a dangerous area.
"They even had to call-in anti-terrorism police."
Around three months ago, David said his father went missing again.
"He was with his carer this time, this time in Leeds train station," David said. "The carer went to the toilet for a couple of minutes and in that time my father boarded a train.
"We looked on the tracker and saw that he was heading towards Scotland."
After a failed attempt to intercept his dad in Newcastle, police picked him up safely North of the border.
David, who works as a pharmacist in Darnall, said: "Younger people with early onset dementia are far more vulnerable to this sort of thing happening.
"Local authorities offer a range of services and there are many different mobile phone apps you can use."
For more information, contact the Alzheimer's Society National Dementia Helpline on 0300 222 1122.