Tooting Bec Lido in South London Swimming Club hosts the 5th UK Cold Water Swimming Championships today.
With water temperatures as low as 1°C, jumping in for the 30 yard races is a challenge in itself.
More top news
A police officer who spent six days crawling the London Marathon in a gorilla costume has finally completed the 26-mile route.
The victim of a "violent and sustained attack" on the top deck of a London bus has been named as Archie Sheppard.
Transport for London has made the badges and accompanying cards permanently available after a successful trial in autumn last year.