Police in Queensland say a man perished in the Simpson desert and another was found close to death after their four-wheel drive became bogged.
Police said the pair left Ethabuka Station, in southwest Queensland on Monday and became stranded.
In temperatures well in excess of 40 degrees, the pair decided to walk back to the station, but one died on the way.
The second man was found by another station worker and taken to Mt Isa hospital.
AAP reports he's being treated for heat exhaustion and dehydration.
"He was pretty sick," Inspector Paul Biggin told AAP on Wednesday. It's understood they had little water with them.
Ethabuka Station is owned by Bush Heritage Australia, a group which is helping regenerate the 215,000 hectare site after degradation caused by cattle and feral camels.
Spokesman David Whitelaw said all staff on the station were trained to work out in the field and provided with the equipment they needed.
"It is a very tragic event," he told the ABC.