Badstufolk Knuts lakeside sauna in Norway

THE phrase “thermal regulatory ping-pong” describes the act of taking your body from heat to cold or vice versa. It is good for your heart and circulation, and provides that kick cold water swimmers love.

It could help with numerous other physical ailments, cut depression, and create a new wave of public health awareness.

That is the premise of a new book by Emma O’Kelly, who lives in Dartmouth Park – and the ping-pong she describes is the effect a sauna has on the body.

“I swim at the Lido, Ladies Pond and the Mixed Ponds,” says the author of Sauna, a book that combines idyllic imagery with the history of saunas and an overview of research into its effects.
While cooling down was on her fitness schedule, warming up in a sauna was not. Emma recalls how she used to consider the sauna “an afterthought, always the least appealing option of many a London gym”.

On trips to Finland, Sweden and Norway, she had gazed at saunas dotted through the countryside, red huts with smoke billowing from a corner chimney.

She had also noted how saunas’ popularity in the UK has increased in line with cold water swimming.

On a visit to Finland for the design magazine Wallpaper, she was invited to a sauna.

Hackney community sauna

“We got beers and snacks and went down to a sauna by a lake,” she recalls. “We spent hours unwinding, relaxing. I came out and thought – this is not sauna as I know it. It was incredible.”

Emma had long gazed wistfully at Scandinavian and Nordic design, and had an idea it would make for a visually arresting book, with essays on the aesthetics and its evolution of the classic log cabins dotted about the northern European archipelago.

Working with photographer Maija Astikainen, they embarked on a 10,000-kilometre campervan trip to find uncover sauna secrets.

In 2019, Unesco gave the Finnish sauna a special standing.

“It joined a list that includes things like Jamaican reggae, bee-keeping in Slovenia, grass mowing in Bosnia,” explains Emma.

Then the pandemic hit and public health became a hot topic.

From here was born a book that seduces you through pictures of perfect landscapes and words about how a sauna can improve your lot.

It’s a powerful combination.

Emma tells the story of the sauna in Finland, Norway, Estonia and Sweden, with roots in ancient history.

Early saunas were semi-underground, and could also be found across Ireland and Scotland.

Over time, it developed into the wooden hut

“Lots of countries lay claim to be the originators,” she says.

What is clear is the sauna developed across northern europe at different speeds.

“One of the earliest dates from 2,000 BC in Finland,” says Emma.

The Finns are aware of the impact the sauna has had on their society.

“They have museums celebrating them,” says Emma.

With a range of places developing versions, a sauna is not always a pine-lined hut with hot coals and a bucket of water.

Emma O’Kelly

An early development was the smoke sauna, which began with chimney-less shacks.

A large fire is set and the smoke fills the room.

Then a door is opened and the user steps in.

“They are for real connoisseurs,” adds Emma. “Everything is covered in soot. It has an amazing smell – you can taste the smoke in the back of your throat. It is an otherworld experience.”

In the Baltics, saunas are not public facing – they are found in private homes and summer cottages.

“The Baltic traditions are incredible,” says Emma. “They are tied up with rituals and mysticism. They used to believe the steam was connected their ancestry.”

Emma has looked at different customs, one of which includes “whisking” – using branches to exfoliate the skin. “It heightens your experience of the heat,” she says. “It takes you into a different mental state. The sound is like a snare drum and it becomes a multisensory space.”

The link with public health is crucial.

A 26-year research project by Finnish doctor Jari Laukkannen followed 2,000 men and found that those who took regular saunas were half as likely to have heart and lung illnesses, as were the risks of strokes, pneumonia, Alzheimer’s disease and dementia.

“It has been shown to be good for blood pressure,” says Emma. “It aids circulation. It is excellent for recovery post-exercise.”

The heat dilates blood vessels and improves circulation, but Emma points out it is not the same as working out – it doesn’t build muscle nor strip away fat. Instead it is best done after a workout, improving recovery and lessening the likelihood of stress injuries.

Scientists have found that a sauna stimulates your immune system, too – “What’s a fever, after all, other than the body’s way of fighting off an infection?,” asks Emma.

“Sauna simply brings on a feverish temperature without any actual fever and our defence systems kick in.”

Research continues in Scandinavia, while at Coventry University researchers are looking at the effect of heat and cold on the body.

“Clinical trials are hard to do, because of the other factors on someone’s wellbeing, but the Finnish studies are rigorous and take that into account. It helps with depression, autoimmune diseases, and ailments that need regenerative and ongoing help.”

As Maija’s images reveal, saunas can have a DIY aesthetic and be placed in the most beautiful of surroundings, tempting the visitor to stop and strip.

“The Norwegians are experimental and have brilliant architecture,” says Emma. “They have interesting design concepts.”

Emma is an ambassador for the British Sauna Society, made up of doctors and sauna aficionados, and discuss research and publicise benefits.

She has seen a marked rise in popularity.

“In the UK, people are not familiar with saunas – but look at how people have reacted to cold water swimming,” she says.

A sauna has brought new swimmers to the Lido – and this is mimicked across the country.

“We hope councils see they bring people to beaches and pools,” says Emma. “We want more saunas to be more accessible. This is about public health, recognising they can be great for everyone.

“And it is much easier to go for a cold water swim if there is a sauna to tempt you afterwards. It is an opportunity to try something new that is good for your health – and that is what my book is all about.”

• Sauna: The Power of Deep Heat. By Emma O’Kelly and Maija Astikainen, £18.95