On 22 January 2012, Blue Peter's Helen Skelton completed an epic 500-mile trek to the South Pole for Sport Relief, using three modes of transport: kite skiing, cross country skis, and - in a world first - by bike. This is the story of how she made that gruelling journey, experiencing temperatures twice below that of a household fridge freezer. As well as dealing with temperatures of -36 degrees, she had to battle with blisters, not washing for weeks on end, and a cough that threatened to give her pneumonia.

• Claudia Winkleman