A Newport plumber who is working in Antarctica will switch off the lights at the research base he is at as part of the Earth Hour campaign.
Gareth Collier is asking his Halley research station colleagues to switch off all non-essential lights on the base at 20:30.
Conservation charity WWF stages Earth Hour to highlight climate change.
Lights will also be turned off at Big Ben, the Empire State Building and the Sydney Opera House among others.
Speaking to BBC Wales from the British Antarctic Survey's Halley station on the Brunt ice shelf, the 25-year-old said he was working for a building contractor in Bridgend when the opportunity to head south came up.
'Chance of a lifetime'
"I was just flicking through the pages of the newspaper and saw an advert for plumbers," he said.
"I filled out the form and went for an interview in Cambridge - there was quite a lot of competition for it.
"I was just basically looking for a change, the chance of a lifetime."
After basic training in activities like rock climbing, abseiling, and dealing with spinal injuries, Mr Collier landed in Antarctica on 5 November to start an 18 month working stint on the southern continent.
He says there is a lot of hard work and little opportunity to leave the base - let alone return home to Wales.
"It's constant - in the summer it's six days a week, sometimes seven," he said.
"In the winter you get weekends off - we only ever get one week off during midwinter in June, but you still have the responsibility of looking after things if there's an emergency.
"Once you're here, you're here - the ships have gone for the winter and flying is so expensive at £15,000 a time."
Mr Collier is part of a small permanent team manning the Halley research station during winter temperatures as low as -55C.
"At the moment we have 14 people here during the winter - we won't see anyone else until December when the summer comes," he said
"Last summer we had 105 people here as they were building a new base - next summer it'll be more like 70."
Despite the cold and remote workplace, Mr Collier said there is plenty to do and not just plumbing.
"Working in the new build, I have a daily check list to go through," he said.
"Yesterday we were using fuel drums to mark out routes. The next day I could be working on two big melting tanks for drinking water, making sure they work, or maintaining the sewer plant."
He admits that work in sub-zero temperatures is challenging.
"It's extremely difficult in these conditions -25 degrees, with the wind chill more like -35," he said.
"You can only work for five or 10 minutes at a time outside before you have to come back in to get warm again.
"A five minute job could take an hour."
Mr Collier said there's a good team spirit among staff at the base, which includes two women.
"We all try to just muck in - I might help the electrician, do some labouring, cleaning. Everyone mucks in.
"At the weekend we can go down to the coast for some rock climbing or abseiling - it's pretty good."
Hopes of return
Mr Collier said staff at the base are planning to mark the WWF's Earth Hour climate change campaign at 20:30 local time on Saturday, when supporters around the world will be turning off lights for one hour to save energy.
"I've asked the base commander if we can switch off all non-essential lights," he said.
"We'll have to leave things like generators on because they take too long to start up again. We'll try and do what we can."
Mr Collier is due to stay at the base until March 2013, but he says there's every chance he'll want to return to Antarctica.
As a single man, he says he finds it easier to be away from home than some of the married members of the team, although everyone is coping well.
"I'm really enjoying myself - it's a once-in-a-lifetime chance," he says.
"My old firm in Bridgend have offered me a job when I return home to Wales, but I'll definitely have a think about coming back here again."