Police are appealing to the public for any information of a vulnerable missing man from Aylesbury.
Mr Wheeler is 5ft 9ins tall, of stocky build, with short brown hair and brown eyes.
He was last seen in the Bierton Road area where he was wearing grey tracksuit trousers, a grey t-shirt, jacket and sand-coloured boots.
More top news
Annual rail figures reveal the most overcrowded service in spring/autumn 2015, was an early morning train from Brighton to Bedford.
Thursday's weather for the west of the region
Thursday's weather for the east of the region