Concerns are growing for a Sheffield pensioner with Alzheimer's who has not been seen since yesterday.
George Rodgers, aged 84, left his home in Ecclesfield, at around 4pm and has not been seen or heard from since.
He was reported missing last night.
Police officers searching for Mr Rodgers are being helped by members of the Woodhead Mountain Rescue Team.
The OAP is white, with thin white hair, around 5ft 6 ins tall, and of a medium build.
He was last seen wearing blue jeans and a blue long-sleeved polo shirt.
Because of his medical condition, Mr Rodgers wears a medical wristband containing his details.
Mr Rodgers, who lives with his wife, left his home intending to walk to a local park but failed to return.
The father-of-three, who used to work in accounts for British Steel, has lived in Ecclesfield for nearly 50 years.
He is a keen Sheffield United fan.
Chief Inspector Richard Lambert, who is leading the search for the pensioner, said he is 'very concerned' for his welfare.
"George is 84 and has reasonable physical mobility so it is common for him to go out walking. He has walked to Barnsley before," he said.
"But he has advanced Alzheimer's and the longer he is missing the more concerned we are becoming because he is vulnerable.
"He has no access to money and is not dressed for the heavy rain expected later today.
"He was also out yesterday - the hottest day of the year so far - and overnight.
"We have not stopped working on this since he was reported missing, with searches of all the open and wooded areas around his home carried out with help from mountain rescue team volunteers.
"We have also visited all his relatives and previous places of employment - anywhere he may have gone, but we are now reliant on sightings from members of the public."
He said Mr Rodgers may appear confused.
Anyone with information on his whereabouts should call South Yorkshire Police on 101.