Authorities are searching for an 18-year-old English backpacker missing from a property in outback Queensland.
He was last seen on Tuesday afternoon when he left Upshot Station, 130 kilometres south-west of Longreach, but failed to return.
Police Sergeant Dave Perry says the man has only been in the area for a few weeks and is not familiar with the terrain on the property.
"There is 32,000 acres there, but we are concentrating on an area," he said.
"The missing person has had a bit of survival training - there's some indication that he may wish to pursue a career in the armed forces when he gets back home.
"He may have been using some of the rougher country and the jump-ups to improve his fitness.
"Lack of water, the heat, venomous snakes and injury are probably our greatest concern."
Sergeant Perry says planes and horses may be used in today's operation to try and find the man.
"EMQ has supplied a helicopter which has come from Roma, which contains two pilots, a paramedic and a doctor," he said.
"Some of the neighbours have supplied planes to assist with the search.
"We're going back out this morning hopefully with some SES - they'll be a helicopter, maybe some other planes and people on foot and maybe some people on horses to assist in the search."
The man is described as Caucasian, 180 centimetres tall, with a muscular build and short dark hair.