NNot long ago, a cold plunge bath was used as a punishment for people considered insane. Now, ice baths are being praised by celebrities and social media influencers as a way to treat depression, lose weight and boost immunity. Still, cold water immersion should be more widely recognized as a potentially deadly activity, according to academics, charities and even cold plunge advocates.
“If these were people taking a leisurely walk, that would be fine,” says Professor Mike Tipton, who has been researching cold water immersion for 40 years. “Sixty percent of cold water deaths occur in the first minute of immersion. You take a tropical animal and drop it into water at 12 degrees Celsius – that is not a risk-free activity.”
Last week, a coroner ruled that Kellie Poole died of an undiagnosed heart condition caused by a cold water immersion therapy session in the River Goyt in Whaley Bridge, Derbyshire, in April 2022. The 39-year-old developed a sudden cardiac arrhythmia after entering the water was 10.7 degrees Celsius. She complained of a headache, fell over and later died.
Poole’s mother and Kevin O’Neill, who led the session, both said people offering cold water immersion as a therapy should now be regulated. Although the company running the session was not responsible for Poole’s death and could not have foreseen her negative reaction, Peter Nieto, senior coroner for Derby and Derbyshire, agreed and said he would produce a report on the prevention of future deaths. The Department of Health and Social Care said it had no plans to regulate the activity.
The American Heart Association has done that warned against cold therapyand the British Heart Foundation (BHF) said people with heart conditions should consult medical professionals before such treatments.
Jo Whitmore, senior cardiac nurse at the BHF, said people with heart conditions are safest in water between 26 and 33 degrees Celsius. “Entering very cold water can lead to a shock that can cause a faster heart rate, higher blood pressure and shortness of breath.” This, she added, could “lead to hypothermia and increase our stress hormone levels, increasing the risk of abnormal heart rhythms and possibly even cardiac arrest.”
From Hippocrates in ancient Greece to Charles Darwin via Thomas Jefferson and Florence Nightingale, experts have advocated a cold plunge. “The Romans had a frigidarium in addition to all the hot baths,” Tipton said.
Yet it is also used as punishment. In the 19th century it was used on those held in Ireland’s Limerick Asylum, and the practice was subsequently banned. a man known as Danford died there in 1873 after “immersion in a cold plunge pool”.
Wim Hof, the Dutch motivational speaker and self-proclaimed Iceman, took up the baton for cold water immersion, and Lewis Pugh completed an endurance swim across the North Pole in 2007. Further stories from top athletes such as Andy Murray and Jessica Ennis-Hill using ice baths added credibility.
The current trend emerged during the Covid lockdowns, Tipton said, adding that an open water swimming group at Perranporth in Cornwall “went from 25 members to 1,000 over the course of the lockdown period”.
Fans report that the depression has lifted, the immune system has been strengthened and he feels awake and more alive. With celebrities like Madonna and Holly Willoughby being seen in ice baths, the trend has now become so mainstream TikTok’s lists #coldplunge with 1.5 billion views, as consumer news websites rank the best cold plunge pools of 2023, from £100 barrels to £13,000 plunge pools for the backyard – like a jacuzzi, but with an ice maker.
Some organizations do point out the risks. On Sunday, Surfers Against Sewage kicks off its Dip A Day in October campaign to raise money to protect the oceans, but they publish prominent safety guidelines.
The Outdoor Swimming Society, founded by journalist and author Kate Rew to promote swimming in rivers, lakes, lidos and seas, has published guides and warnings on its website. “Some people feel very high when they get into cold water,” she said. “People have described it as the high they get from going to the club, or the second hour of a marathon.
“Then the vast majority of people just find it cold, unpleasant and exhausting. We don’t hear about these people that often.”
To her surprise, Rew was recently converted after a trip to Finland involved a quick dip in a frozen lake followed by a sauna. Now she has a cold metal bath in her backyard. “It’s the first thing I do when I wake up: skinny dip in a bathtub,” says Rew, author of The handbook for outdoor swimmers.
“I look at the sky and the weather, the wind in the trees, and I have this moment in a day that is really focused on joy. I don’t think I have the physiological trait that some people have that makes them addicted to colds. I just think it’s a moment to catch my breath. And I like to be tough enough.
“There is little scientific evidence to support the well-being benefits of cold water. There is a dominant narrative that it is very good for you, to the extent that everyone should adopt it. But it is not scientifically substantiated. There isn’t much research, other than a lot of anecdotal evidence. So people must be given the freedom to follow their own inclinations.”
Tipton reviewed the scientific literature on cold water immersion and said there are hypotheses for some of the claimed effects: Cold shock causes the release of stress hormones, which make people feel alert. There are hypotheses that immersion could reduce inflammation, the body’s way of protecting itself against infections, and people who do cold water therapies say they catch colds less often.
“But they’re just hypotheses – there haven’t been any good randomized controlled trials,” Tipton said. Trials can isolate the effects of cold water from other things: exercising, floating, overcoming a challenge, or being outdoors. “Then maybe you can activate it in other ways.
“I wouldn’t do anything that was seriously stressful without checking that I was fit and healthy enough to do it,” Tipton said. “But it’s also how you deal with it: the longer you spend in it, the greater the risk. We estimate that if there are any benefits, they will all be achieved within a few minutes.”