Intended for healthcare professionals


Why I . . . swim outdoors in cold water

BMJ 2022; 379 doi: (Published 06 December 2022) Cite this as: BMJ 2022;379:o2899
  1. Kathy Oxtoby
  1. London

This Christmas, as we’re cosying up in front of the fire, consultant psychiatrist Jon Goldin has a more bracing festive activity in mind. Kathy Oxtoby reports

“I’m looking forward to swimming in cold water at the Hampstead Heath Mixed Pond. It’s a nice way to start the festive season,” says Jon Goldin, a consultant child and adolescent psychiatrist at Great Ormond Street Hospital, London.

It’s not the first time he’s taken a cold water plunge during the Christmas holidays. “A few years ago I took part in Perranporth Surf Lifesaving Club’s traditional Boxing Day dip, where I swam off the coast of Cornwall.

“We swam in our swimming costumes and Santa hats. It was very cold but great fun. It woke us all up and was a good way of working off Christmas dinner. And after the shock of the cold water, when you return home to the warmth you feel a sense of calm and wellbeing.”

Goldin believes it’s important for doctors to look after their mental health and wellbeing to build therapeutic relationships with patients and be good clinicians. “I say to trainees that a medical career is a marathon not a sprint. We need to pace ourselves and look after ourselves.”

For Goldin, swimming is a way to destress. “I love swimming outdoors in cold water. It’s invigorating and ‘cleanses’ you of stress. And it’s great to be out in nature, swimming in the sunshine, looking up at blue skies.”

Since he was a child, Goldin has enjoyed swimming. “I swam at school and at university. As a junior doctor I worked in Australia for a year, where I got a real taste for swimming in cold water.” As a consultant, over the past eight years he has “rediscovered the joy.”

“I’d been doing triathlons to exercise and stay healthy, and as well as running and cycling, you swim outdoors. Increasingly I found I was enjoying swimming the most. You find yourself swimming in places you wouldn’t normally, like lakes or the Thames.”

Now, three times a week, Goldin visits his nearest pond in Hampstead Heath or the lido on Parliament Hill, where he combines his love of exercise, swimming, and the outdoors.

Typically, he swims for 40 minutes covering 1500 m. “Sometimes I’ll go swimming at 7 am. I come to work feeling wide awake, refreshed, and ready for the day.

“Sometimes I swim at the end of the day, and if it’s been a stressful one, I find it a great way to transition from work to home life.”

He swims outdoors mainly from spring through to autumn, when water temperatures range from 20°C in summer, down to 10°C in spring and autumn—“in terms of temperature they’re slightly kinder months compared with winter, which can be as cold as 4°C.”

When it’s colder he wears a swimming cap, gloves, and rubber boots to stay warm, and he occasionally wears a wetsuit when training for triathlons.

This July saw the highlight of his cold water swimming experience so far. “I travelled to Iceland where I swam in a place called Silfra, which is where the Eurasian and American tectonic plates meet and where the TV series Game of Thrones was filmed.

“It was one of the most amazing experiences of my life. The water was 2°C and very clear—there was 100 m visibility, so it was like glass. It was so beautiful looking at the colours of the rock formations and plants. There’s a whole underwater world people often don’t see.”

He finds outdoor swimming is good for his physical and mental health, which means his hobby also benefits his patients and colleagues. “If you feel better in yourself you’re going to be a better clinician.”

Goldin hopes to encourage others to take up this bracing activity, and—perhaps—even take the plunge this Christmas. “Consider swimming in cold water outdoors as a way of relaxing and staying healthy. It’s enjoyable, rejuvenating, and a great counterbalance to the daily challenges of our working lives in the NHS.”

How to make a change

  • Check out places where it’s safe to go cold water swimming, such as a nearby lido or pond

  • If you’re planning to swim regularly at your local lido, then it’s cost effective to invest in a season ticket

  • If you’re swimming in the sea or a tidal river, be aware of currents and look out for boats

  • Invest in a decent pair of goggles to protect your eyes, and ear plugs to prevent ear infections or blocked ear canals

  • Be aware that cold water swimming can lead to hypothermia if sensible precautions are not taken. As a rough rule of thumb, one can be in the water for 1 minute in water of 1° C, 5 minutes at 5° C, and 10 minutes at 10° C

  • Check out the website for further information

  • For further reading, Kathy Rogers’ The Outdoor Swimming Guide (Vertebrate Publishing 2021) is a useful book