The horrifying hidden dangers of saunas: We reveal the shocking risks to your health of one of Britain’s favourite activities – after former model Mileva Brooks collapsed and died

Before Mileva Brooks entered the sauna at her local gym, she stopped to read the safety warning printed on the door.

Satisfied, the 75-year-old entered the heated, wood-panelled room at 2.15pm on August 26, 2022.

However, what was supposed to be a relaxing afternoon of leisure, quickly turned into a nightmare.

Soon after, other gym members who entered the sauna became concerned about Mileva’s health when they noticed she appeared to be having breathing difficulties.

Another customer activated the emergency button, alerting staff, and the sauna was switched off at 3.16pm.

An ambulance quickly arrived and Mileva was rushed to Cheltenham General Hospital.

But it was too late. The former model died three days later.

At an inquest into Mileva’s death, in September 2023, the coroner concluded that the only possible cause of her death was heatstroke – a life-threatening condition triggered by overheating, where the organs can fail.

And, last week, it was revealed that Mileva’s daughter, the actress Milanka Brooks, is now suing the gym chain, Everlast, which operates the sauna.

Ms Brooks, 41, who has starred in two episodes of the Netflix TV show Black Mirror, is seeking £100,000 in damages.

Lawyers for Frasers Group, owner of Everlast gyms, are understood to have not filed a defence for the claim as yet.

The actress has often spoken of her and mother’s close relationship, with posts on social media calling her ‘the light and inspiration of my life,’ her ‘partner in crime’ and ‘best friend in the world’.

Worryingly, Mileva Brooks is not the first Briton to come to harm in a sauna in recent years.

Earlier this year, a woman in her 70s was rushed to hospital in Birmingham after suffering a heart attack and multi-organ failure triggered by heatstroke from a sauna.

The unnamed woman survived but spent 12 days in hospital as a result.

International research has previously suggested that roughly two in every 100,000 sauna sessions leads to a death.

But experts are now warning that more sauna deaths could occur in the UK in the near future.

Experts say that the rapid rise in popularity of saunas in the UK means that many inexperienced users are unaware of the crucial steps to take – and the dangerous mistakes to avoid – to reduce the risk of life-threatening health complications.

They also reveal that there are certain people who are significantly more at-risk of falling ill in a sauna than the general population.

‘Saunas have many health benefits, but they are definitely not risk-free,’ says Dr Matt Maley, a body temperature expert at Loughborough University.

‘In our research laboratory, when we put people into hot rooms, we have to carefully monitor their body temperature and, the moment it hits a certain number, we terminate the experiment.

‘People can go into saunas and raise their body temperature to these same levels, but the key difference is that there isn’t a team of scientists on-hand to pull them out if they get too hot.’Mileva

So, how can you avoid dangerous sauna complications – and who should steer clear of them altogether?

Saunas are enclosed wooden rooms that are typically heated to a temperature of around 80C (176F). The trend originates from Finland.

Sauna-lovers say the hot rooms have a variety of health benefits including managing stress and easing muscle pain.

However, research suggests the most concrete benefit of saunas is improved heart health.

A 2015 study that followed 2,300 Finnish men over 20 years found those who visited saunas around four to seven times a week were less likely to die of heart attacks and strokes than those who did not.

The UK is currently in the midst of a sauna craze, with the number of the hot rooms open to the public tripling since 2023. There are now around 150 of these community saunas in the UK.

A number of celebrities, including Gwyneth Paltrow, Sabrina Carpenter, Maya Jama and Rita Ora, have also taken to social media in recent years to share their love of saunas.

However, experts say this increase popularity puts more people at-risk of falling ill in saunas.

One danger is that the heat can trigger deadly complications in patients with undiagnosed heart problems.

‘Saunas put the heart under a lot of stress,’ says Dr Matt Maley. ‘Most people have a resting heart rate of around 60 beats per minutes. But, once you get into a sauna, this can very quickly get up to 110, even 130, beats per minute.

‘So if you have a heart problem you don’t know about, this could be enough to trigger a serious cardiovascular event like a heart attack.

‘This stress can also cause blood clots to break off and start to move around the body’. Experts say this can eventually block blood flow, leading to deadly complications.

However, experts agree that the biggest risk posed by saunas is heatstroke – the most common cause of sauna-related deaths.

The average human body temperature is around 37C (86F). Research suggests that heatstroke begins to occur when the body reaches 40C.

At this temperature, the body can no longer keep itself cool and, as a result, the heat begins to inflict serious damage on vital organs like the brain, heart and kidneys.

But experts say that, even before the body reaches 40C, damage can occur.

‘Anything above 38C is going to begin to cause problems in the body,’ says Dr Maley. ‘And that’s a temperature you can reach in a sauna.’

For this reason, experts say it is important to look out for the early warning signs of heatstroke.

These symptoms include dizziness, confusion, blurred vision, fast breathing and cramps.

‘If you experience any of these symptoms in a sauna, you should get out,’ says Ben Wright, a lecturer in exercise physiology at the Oxford Brookes University.

Experts say that older people – typically those over 75 – have an increased risk of heatstroke.

‘As people age, the body becomes less effective at cooling itself,’ says Wright. ‘This is why the majority of deaths that happen during heat waves are amongst elderly people.

‘Part of this is due to the fact that the number of active sweat glands goes down over time. Without the ability to sweat, the body will continue to heat up, raising the risk of heatstroke.’

However, heatstroke can happen at any age, particularly when sauna users stay in the hot rooms for longer than recommended.

Research suggests that inexperienced sauna users should stay in for no longer than 10 to 15 minutes. Any more time can raise the risk of serious health issues.

‘The problem is that many people stay in far longer than this,’ says Prof Mike Tipton, a human physiology expert at the University of Portsmouth.

‘If you’re paying for an hour in the sauna, you will try and get the most for your money by staying in as long as possible.’

Another factor which increases the chances of heatstroke is dehydration – which impacts the body’s ability to produce sweat.

This means people who enter a sauna straight after exercising, for example in the gym, are more at-risk.

Surprisingly, experts say people who use saunas straight after swimming in cold water also face the same risks.

This is because being in cold water increases urine production, drawing water out of the body.

‘In recent years, there’s been a growing number of saunas on beaches,’ says Prof Tipton. ‘This could cause dehydration problems, particularly if people are going back-and-forth between the sauna and cold water.’

For this reason, experts say sauna-users should make sure to drink plenty of water before entering, and also bring a bottle of water into the room.

However, research suggests that the bigger risk factor behind saunas death is alcohol.

Studies show that around half of people who die in a sauna had been drinking. This is largely due to the fact that alcohol dehydrates the body. But, booze can also affect the body’s ability to maintain blood pressure, slowing its response to high temperatures.

Research also shows that people who use saunas on their own are more at-risk of dying than those who go with other people.

Experts say this is because people who are alone in saunas – like Mileva Brooks – do not have someone with them to spot the signs of heatstroke and help them out of the heated room before they fall gravely ill.

‘Avoid alcohol and make sure to go with someone else, are two bits of advice I would always give to beginner sauna-users,’ says Ben Wright.

‘And, of course, be sensible with how long you stay in.’