Police are increasingly concerned for the welfare of Mr Stephen Crawford who was wearing just a dressing gown when he went missing.
Overnight temperatures plummeted to freezing and local people as well as the Search and Rescue Teams joined police in trying to find the 55-year-old.
A PSNI spokesperson issued a photo of the man and said: "He was last seen at the hospital roundabout at 9.05am on Tuesday.
"We have Search and Rescue, dogs, and as many resources as we can put into finding this man.
"The last known clothing we know about is a grey dressing gown with a hood and a pair of blue asics trainers with a white stripe on them.
"Any sightings please contact us as a matter of urgency. Thanks to all that have given us information so far. Ref 287 17/12/19."
"In this season of goodwill let's do everything we can to bring Stephen home to his family safe and sound."