Five men are putting their bodies on the line, climbing to the peak of Mount Kosciuszko in the middle of winter wearing nothing but their swimming costumes in the hope of raising $100,000 to combat youth depression and anxiety.
The group of friends from Sydney - made up of teachers Ben Anderson, Blake Leonard and James Raxworthy, broadcasting producer Adam Leonard and trainer Michael Hole - came up with the idea for 'Kossie in Cossies' after seeing teenagers struggle with anxiety and depression.
They will undertake the feat in July, when the average high is expected to be around 0 degrees, and will donate all the funds they raise to beyondblue.
One in six young Australians have experienced anxiety in the past 12 months, one in 16 have experienced depression over the same period, and one in four have a mental health condition, according to beyondblue.
Suicide is the biggest killer of young Australians and accounts for the deaths of more young people than car accidents.
Anderson, who is a teacher and year advisor at Engadine High School, told SBS they wanted to be role models for their students and show them what you can achieve if you put your mind to it.
"Every day we see depression, anxiety, suicide - really, really serious things - and we have seen the pain and damage these issues can cause young people, their friends and their families," he says.
"So we wanted to try and do something to set an example that if you're mentally tough you can really do anything."
They set upon the idea to climb a mountain in the budgie smugglers after being inspired by a Dutch daredevil Wim Hof, nicknamed 'The Iceman', who has climbed Mount Kilimanjaro in nothing but shorts and shoes.
"We heard about this guy and we thought, you know what, let's give it a go," Anderson says.
"It's kind of a really physical and tangible way for kids to relate to overcoming challenges."
The group have been acclimatising using ice baths - or rather, wheelie bins filled with eight bags of ice and water - which are a chilly 4 degrees.
They have been training since November and are now able to withstand 13 minutes submerged up to their necks in the water.
"It's hilarious and it's cold too," Anderson says of the wheelie bin baths, "but it's kind of serious, trying to prepare ourselves for the very, very cold. It can turn so quickly up there."
The group will take backpacks full of safety equipment and will be traveling with a guide. "We aren't really interested in dying on the mountain do we're very smart in what we're doing," says Anderson.
The five men did a trial run up Mount Kosciuszko dressed in shorts in late August last year when temperatures dropped to -1.
"It was so funny because we were just smashing up the mountain and we were walking past all these people with all their official gear and walking sticks and we just walked past and gave them a really chipper 'good morning!', and just walked past in our shorts," Anderson says.
With a goal of $100,000, they have so far raised about $24,000 thanks to a few organisations and a fundraising page.
But beyond the money, "our aim is to be entertaining and humourous and do something that leads to widespread intrigue, curiosity and interest," Anderson says.