Search crews have resumed the hunt for a Victorian hiker, missing in snowy Tasmanian wilderness, with authorities worried about the safety of three other people in near-freezing conditions.
Michael Bowman, 57, was expected to finish a walk at Lake St Clair visitor centre in the state's Central Highlands on Saturday, but hasn't shown up.
An air, ground and water search for Mr Bowman continued on Tuesday morning, while police also raised concerns for an adult and two youths believed to be near Lake Pedder in the state's rugged southwest.
The trio may have travelled in a white Toyota ute to the area on Sunday night or Monday morning.
"Police are seeking further information with a view to divert resources including the Westpac Rescue Helicopter to search for these three people," Acting Inspector Phil Curtis said.
Every hut on the popular Overland Track will be checked by helicopter for bushwalkers who may be in trouble.
About 30 people are understood to be hiking in the region, including a Hobart school group of 10, who are reportedly safe and intending to return on Tuesday.
Mr Bowman, an experienced bushwalker from Melbourne's east, last contacted family about a week ago and hasn't activated his emergency beacon.
Bureau of Meteorology forecaster Matthew Thomas told AAP he has serious concerns for any person left out in the cold.
"Cold temperatures and strong winds increase the risk of hypothermia," he said of overnight conditions.
Police believe Mr Bowman set-up camp in a sheltered area to do day walks in the Mt Cuvier region before he became stuck in bad weather.
Several bushwalkers had to be rescued on Monday, including a Brisbane man aged in his 40s from the north-west end of Lake St Clair.
Another two NSW hikers were plucked from the Walls of Jerusalem National Park to the south earlier in the day.
People are being urged not to go bushwalking unless they are well-prepared for freezing weather.