HER pupils may already think she’s brrrilliant but one Catford teacher is testing herself to the limits with a 450m swim in near-freezing waters.

Wetsuit-less, Kate Webb will be plunging into perishing temperatures as low as 1C – colder than the deadly waters the Titanic sunk in – for the national Cold Water Swimming Championships 2013.

The nursery teacher at St Saviour’s RC Primary School was selected to swim the two full circuits of the 93-metre-long Tooting Bec Lido - the most extreme race at the biannual event.

The 50-year-old first dipped her toe into cold water swimming several years ago and says the euphoria following the "burning" cold is "addictive".

Ms Webb, who lives off Torridon Road, in Catford, said: "I first started with my husband with a wetsuit in 14 degrees C. He said ‘take it off!’

"I got out and felt amazing and haven’t put it on since.

"When you get into water that is very cold it takes your breath away completely and your whole skin feels like it is tingling and on fire, but you feel so amazing afterwards that you get addicted.

"It’s a real feel-good factor."

She is taking the daring dip for her brother who suffers from Non-Hodgkins Lymphoma disease to raise cash for the Pickering Cancer Drop-in Centre in Tunbridge Wells.

The centre was a life-line for formerly outgoing Paul Webb who took an overdose after a series of blows following the diagnosis including losing his job, home and 18-year relationship.

His sister said: "He had such a tough time with it all. It was especially bad when he took the overdose.

"Losing his family home, every bit of normality that he had – it’s been very tough.

"He is actually in a good state at the moment from this amazing group – they have just given him so much support.

"I just wanted to give something back."

To support Kate’s extreme swim on January 26 click here.