More than 650 crazy cold water swimmers from around the world will descend on Tooting Bec Lido this weekend for the World Winter Swimming Championships.

Swimmers aged 11 to 80 will be taking the plunge in water as cold as three degrees centigrade, with championship races on Saturday, and relay swims and fun races on Sunday.

For the first time the championships are leaving Finland and will be held at the 101-year-old lido in Tooting Bec Common, the largest fresh water swimming pool in Europe.

Each race is a 25m width of head-up breaststroke.

Margy Sullivan, vice president of the South London Swimming Club which is hosting the event, said: "The Finns decided to make the races head-up breast stroke to give the amateurs a chance against the elite. The championship is less about speed and more about coping with the cold, the challenge of the races and having some fun."

A special Finnish sauna and two hot tubs have been brought over specially for the event. Anyone can come and watch, with an entrance fee of £2.

Spectators will be treated to food stalls, a hog-roast, Morris dancing and fine speciality ales while watching the heats, with the finals starting at 2.20pm.

On Saturday there will be talks from cold water enthusiasts including Lewis Gordon Pugh, a renowned long-distance swimmer who has swum in every ocean in the world and Stella Duffy, who swam in the Pacific while fighting breast cancer.

See yourlocalguardian.co.uk next week for full coverage of the event and a video of our reporter Chloe Lambert braving the chilly depths.