Caution advised for swimmers ahead of Bank Holiday weekend

The weather may be warming up but people thinking of taking the plunge this weekend are being urged to consider the risks to avoid cold water shock

As the weather begins to improve, the number of outdoor swimming related incidents unfortunately start hitting the headlines.

While there are anecdotal claims of the mental and physical benefits of outdoor swimming, world-leading experts say it also carries great risk if not done with caution.

Professor Mike Tipton’s research in the Extreme Environments Laboratory at the University of Portsmouth has revealed the main problem for outdoor swimmers is cold water shock (CWI), which peaks in water temperatures between 10-15⁰C.

CWI can affect anyone, regardless of whether they are strong swimmers or not, and increases the difficulty in getting out of the water. It is caused by a rapid fall in skin temperature and can include gasping, hyperventilation, release of stress hormones, hypertension and arrhythmias.

Warm weather, cold water

Professor Tipton said: “Just because we’re seeing sunnier days, don’t be fooled into thinking our seas, lakes and rivers are already warm enough to swim without caution or consideration. The average temperature of UK and Irish waters is 12⁰C.

“We’re already seeing reports of people getting into difficulty in the water, and the best way to prevent this trend from continuing is by raising awareness of the risks of cold water immersion and outline what people can do to swim outdoors safely.”

Between 2018 and 2021, there was a 52% increase in HM Coastguard callouts connected to open-water swimming. Last year there was also a 79% increase in deaths – from 34 to 61 in the UK.

Float to Live

One of the tangible results of Professor Tipton’s work is Float to Live, a campaign by the Royal National Lifeboat Institution (RNLI) that’s been influenced and informed by his research.

With a focus on educating people about what to do once they’re in the water, Float to Live aims to get you over that period where you’ve lost control of your breathing.

Meanwhile, a paper published in British Journal of Sports Medicine outlines what people can do to mitigate any risks associated with CWI. These include taking a medical assessment before entering cold water, nominating a safety observer and agreeing to an emergency signal, and entering the water slowly and gradually.

Rise in popularity

Co-author, Dr Heather Massey, said: “We understand that there have been many reports in the news and on social media of the health benefits of outdoor swimming, which can lead to people wanting to try it themselves.

“We’re still exploring if these claims are supported by science, but what we do know for sure is that people enjoy swimming, especially when the sun is shining.”

Dr Massey is co-leading a study, in partnership with the Sussex Partnership NHS Foundation Trust, to examine the impact of an outdoor swimming intervention for people experiencing symptoms of depression.

She added: “While we’re not discouraging swimmers from taking the plunge, we are urging them to make sure they’re aware of the risks and have undertaken the right precautions before they do.”

For more guidance on cold water shock, click here.

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Abi writes swimming news stories and features for the Outdoor Swimmer website and manages the social media channels. She loves to swim, run, hike and SUP close to her home in Herefordshire. While she’s a keen wild swimmer, Abi is new to the world of open water events and recently completed her first open water mile. She has previously written for The Guardian, BBC Countryfile Magazine, BBC History Magazine and Ernest Journal.