Winter swimmers on Hampstead Heath have been warned to “respect the water” after a struggling bather had to be rescued.

Lifeguards were called into action when the woman “froze” in the Kenwood Ladies’ Bathing Pond’s chilly waters about 40 metres from land – just minutes after attending a talk on winter swimming safety.

She was towed to safety by a lifeguard using a surfboard-like “paddle ski” after a fellow swimmer raised the alarm.

Duty lifeguard Claire Roche, who saw her colleague make the rescue, said: “She was in there for about 15 minutes and her body just froze, basically because she had not habituated, which is what most of the regulars do.

“She had mild hypothermia. We dealt with her, she just needed some reassurance.

“It demonstrates how you have to respect the water when it gets below summer temperatures.

“At this time of year, when the weather is quite mild, people expect the ponds to be warmer than they are.

“We don’t want to put people off but they do need to respect it.”

The rescue took place during a recruitment drive for winter swimmers on Saturday, October 11.

The Kenwood Ladies’ Pond Association (KLPA) arranges the annual event to encourage more women to continue visiting beyond the summer.

“It was pretty ironic, she needed rescuing just after the safety chat,” added Ms Roche.

Year-round swimmer and KLPA secretary Mary Powell said the situation was well handled by lifeguards and the woman was fine afterwards.

“She just needed a bit of warming up and time to recuperate,” she said.

“Generally when we’re advising people who are thinking about winter swimming, we tell them to listen to what their body tells them and not to overdo it.

“You need to be careful but not overly nervous of doing winter swimming, as a lot of us do it.”

She added: “It might take a bit of willpower to get in, but once you have swum in winter you feel fantastic.”

The ladies’ pond was 13C this week and averages about 4C in the coldest months.