The British family of a 21-year-old man missing for more than 48 hours in forest south-east of Perth say they felt helpless and "sick with fear" waiting for news from the other side of the world.
Bayswater resident Robert Fairchild was found by State Emergency Service volunteers early on Tuesday to the relief of his family and friends in Lincolnshire and here in WA.
He had spent two days missing in Mundaring State Forest without food and wearing just tracksuit pants as night-time temperatures dipped below 10C.
"We tried not to think of the worst, but I don't think we slept while waiting for news on the second night," Mr Fairchild's younger sister Jess, 15, told The West Australian.
"We felt sick with fear after realising that it had been almost two days since he had been seen.
"I felt helpless being on the other side of the world from him when I felt that he needed my help."
Describing her brother as a "brilliant guy", very sociable and someone who has made "hundreds of friends" since moving to Australia in 2012, Jess said the family tried to remain positive during the agonising wait.
"We knew that Rob is a very positive person and would not have given up and kept moving throughout his time in the forest," she said.
"Knowing that so many police officers and volunteers were devoting their time to finding him was incredibly reassuring to us."
Jess said the family were hugely relieved when word came through that Mr Fairchild had been found, though their concern quickly turned to his health.
Mr Fairchild was in a stable condition last night in Royal Perth Hospital where he was being treated for hypothermia.
Mr Fairchild had been at a "bush doof" party before he reportedly wandered off about 3am Sunday.
Police said yesterday Mr Fairchild returned to the party about six hours later and was given water by a friend before he again went missing about 10am.
The bush doofs, which can last more than three days and are held in remote locations, are renowned for illicit drug use. But conversations with her brother's friends left Jess "certain" drugs were not a factor in his disappearance.
"Although he has been drinking at the event, we think that wandering off had been an accident and that he could have been found straight away had he not lost his phone while at the party," Jess said.
"I'd like to reinforce how grateful we are to the rescue teams and volunteers who dedicated so much time to him - the way they spared his life with their efforts have made us so thankful.
"We can't express how much the rescue means to our family and his friends."
Health Minister Kim Hames said yesterday that if people were taking drugs at the bush doof then the police "clearly need to take action".
Dr Hames said Mr Fairchild would not be asked to foot the bill for his search.