Footage of the start of the 'Big Chill' International Ice Swimming Association 1km British Championships in Lake Windermere, UK on Sunday.

Hundreds of swimmers took part in the 'extreme endurance winter swimming event', braving the freezing temperatures without wetsuits.

Blue Peter presenter Radzi Chinyanganya was among those attending.

German long distance swimmer Christof Wandratsch won the event with a time of 12.5 minutes, the filmer later wrote online.

Footage of the start of the 'Big Chill' International Ice Swimming Association 1km British Championships in Lake Windermere, UK on Sunday.

Hundreds of swimmers took part in the 'extreme endurance winter swimming event', braving the freezing temperatures without wetsuits.

Blue Peter presenter Radzi Chinyanganya was among those attending.

German long distance swimmer Christof Wandratsch won the event with a time of 12.5 minutes, the filmer later wrote online.

Filmer's description:
With the outside temperature hovering just above zero, and the water temperature not much more, Sunday saw the start of the International Ice Swimming Association 1km British Championships in Lake Windermere. Described as an extreme endurance winter swimming event it is open only to experienced cold water swimmers who have competed in endurance events at internationally recognised winter swims. Radzi from Blue Peter commented on the race as the swimmers took to the water. The race was won by Christof Wandratsch from Germany in a time of 12.5 minutes.

Christof Wandratsch won the event in a time of 12 min 30. He's from Germany, a former English Channel record holder and current International Winter Swimming Association Endurance World Champion. 1990 he won the Lake Zurich Swim. In August 2005 he set the world record for the fastest ever swim of the English Channel in a time of 7 h 03 mins, which has now been broken by 6 mins in 2007 by Petar Stoychev who set at time of 6 h 57 mins.