Doctor Peter Berning, 64, may be a small-town doctor, but for him the world is limitless. It's a long way from the coastal town of Plettenberg Bay to the top of Antartica's highest summit. Berning was one of a team of five who made the ascent in the New Year and climbed not just Vinson Peak, but also an unnamed, uncharted virgin peak that has now been christened Peace Peak.Berning's first foray into white wilderness was in 2005 when, relatively unfit and not wholly prepared, he competed in (and completed) the Polar Race, a 650km walk/ski across the North Pole with his friend, rugby player Dugald MacDonald, and Ted Adams."Dugald asked if I'd thought about going to the Poles," he said. "He wanted to do something extreme. We would never have been able to do it without being part of a race or expedition. Joan [Berning's wife] had heard about dog-sledding expeditions in the North Pole and she planted a seed. "Five years later and Berning's friend Ian Buchan, of financial services group Unlimited, started organising a charity expedition to the South Pole. Berning joined Buchan, his two sons Barney and Zac, filmmaker Sean Wisedal and Nzuzo Mnikathi as they crossed the South Pole in aid of Unlimited's charity Unlimited Child. Mnikathi set the record for being the youngest black person to reach the Pole. At the time he was 19. He was raised by his grandmother, who was a teacher at one of the crèches established by Unlimited Child.That crossing, on January 17 2012, coincided with the centenary of Captain Robert Scott's legendary walk to the South Pole.Two years later the stakes were up. Now, the team - whittled down to the Buchan boys, Ken Watt and Berning - were going to climb not only the highest peak at 4 892m, but also chart an off-the-map mountain."Vinson is not the highest peak, but the weather conditions make it a huge risk," said Berning. "We climbed at -25C, with a wind chill factor of -25C, making it -50C. That's really cold. There's also less atmospheric pressure at the Poles. The air is thinner, so when you breathe there isn't the pressure to fill your lungs. Things can go pear-shaped if you're sick at any time."The team completed the Vinson ascent in ''good weather" conditions before returning to base camp and making the ascent to Peace Peak. This involved navigating a 1km, 40-degree ice wall while carrying about 22kg.The entire expedition took 10 days (7 for Vinson and 2 for Peace, with a rest day in between). Berning's medical expertise was called upon to treat tendinitis in Barney's ankle and to help Buchan with a calf muscle that tore at the start of the ice wall.Berning said there is a huge sense of achievement. "You've set out to do something extraordinary, you've put a lot of training into it, it is fairly dangerous, and a lot of people have failed. When we got to the top there were tears."..