Prince Harry warms up for South Pole charity trek 14 November 2013 Last updated at 01:12 Prince Harry and a team of wounded servicemen and women are to gather in Trafalgar Square later ahead of their charity expedition to the South Pole. The group are due to fly to Cape Town, in South Africa, on Sunday. Two days later, they fly on to Antarctica. The group will spend time acclimatising to the extreme cold and altitude before walking 208 miles (335km). At the Walking with the Wounded departure event in central London, the prince will receive a South Pole flag. He is also expected to make a short speech and unveil the Walking with the Wounded trophy. Moving ice-shelves As part of his expedition training, Prince Harry, an Army pilot who has served in Afghanistan, spent a night in a sub-zero Army test facility in September. He and four team-mates, who all lost limbs in Afghanistan, were subjected to ambient temperatures down to -35C (-31F) and wind speeds of 45mph (72kph). In the Antarctic, the team will face even lower temperatures of -45C (-49) and savage 50mph (80kph) winds. They expect to trek for between nine and 12 miles a day (15 to 20km), dragging 11-stone (70kg) sledges, and are likely to encounter vast crevasses, moving ice-shelves, glaciers and snow storms. The aim is to beat teams from the US and the Commonwealth to the southernmost point on the globe. The actual race begins on 30 November and competitors are expecting to reach the geographic South Pole by 16 December. Each team will have a guide and mentor, and they will all be followed by a support team in case of emergencies. The expedition aims to highlight the courage of men and women injured while serving their country. Walking with the Wounded, which has Prince Harry as patron, raises funds to re-train injured or sick service personnel to help them find another career. Previously, one of Harry's team-mates - Major Kate Philp, from Knightwick in Worcestershire, who lost a leg on active service - said the prince's Army background made him a good team-mate. He knows what he's doing. He's got his military training... so he's a good extra pair of hands," she said. Harry's other team-mates are Sgt Duncan Slater, from Muir of Ord in Scotland, who lost both his legs in a blast in Afghanistan in 2009; Capt Guy Disney, from Oxford, who lost his right leg in a rocket attack in 2009 and Capt Ibrar Ali, from York, who lost his right arm in a roadside bomb in 2007. In 2011, Harry took part in a Walking with the Wounded fund-raising expedition to the North Pole, but withdrew early to attend his brother's wedding. He did not take part in last year's failed bid to conquer Mount Everest because of his military commitments.