Are saunas the health miracle we’ve been led to believe? Scroll through social media, and you’d think saunas and cold plunges are the ultimate cure-all—boosting immunity, burning fat, and fixing everything from joint pain to low mood. But here’s where it gets controversial: while the hype is real, the science is still catching up. Experts caution that the reality is far more complex.
Dr. Heather Massey, an associate professor of extreme environments and physiology at the University of Portsmouth, puts it bluntly: ‘Many people swear by hot and cold exposure, but we don’t yet have enough evidence to say it’s definitively good for you.’ Our bodies, she explains, are ‘remarkably efficient’ at maintaining a stable core temperature, typically between 36.5°C and 37°C. Yet, in our modern lives, we rarely challenge this system, often staying in temperature-controlled environments like heated homes or air-conditioned offices.
Exposing the body to heat or cold creates a mild stress, which may trigger adaptive responses. And this is the part most people miss: it’s this stress response that underpins the appeal of saunas, which are now a staple in gyms and spas. For some, it’s a post-workout treat; for others, it’s the main event. Many regulars insist that 15 minutes of intense heat works wonders for their body and mind. But does it?
There’s no denying the immediate benefits. ‘When you sit in a sauna and sweat, you might feel looser, more mobile, and even notice aches and pains easing,’ Dr. Massey explains on BBC’s What’s Up Docs podcast. ‘But the question is whether these are long-term health benefits or just psychological.’ A recent study on hot tub use showed changes in insulin and blood pressure, hinting at potential benefits for chronic conditions. Yet, Dr. Massey urges caution: ‘We’ve never done a proper sauna trial. I suspect we’ll find benefits eventually, but we’re not there yet.’
For now, she suggests enjoying saunas for the ritual and how they make you feel, rather than as a guaranteed health fix. And if you do try them, ‘ease in gradually,’ she advises, especially if you have underlying health conditions or are pregnant—always consult your doctor first.
But what about cold water swimming? This trend is booming, with early-morning dips in beaches, lakes, and rivers becoming a common sight. Dr. Massey, a seasoned cold-water swimmer who’s competed in the world ice-swimming championships, describes the initial experience as ‘painful,’ but that’s precisely what draws people in. The shock of cold water triggers a surge in heart rate, blood pressure, and stress hormones like cortisol and adrenaline. ‘This response peaks in about 30 seconds and then quickly subsides,’ she notes. With repeated exposure, the shock response diminishes by around 50%.
Here’s the controversial question: Are the benefits of cold-water swimming due to the temperature itself, or the surrounding factors? It’s often done outdoors, with others, combining nature, movement, and social connection. ‘These elements are all interlinked,’ Dr. Massey says. Podcast host Dr. Chris van Tulleken adds, ‘We don’t know if the benefit is the cold water or the camaraderie of doing something challenging with others.’
For Dr. Massey, the key isn’t temperature—it’s enjoyment. ‘People who do Parkrun weekly describe the same buzz as cold-water swimmers,’ she observes. ‘What matters is finding something you enjoy, can do regularly, and ideally share with others. Building a friendship group around an activity can reduce psychological stress.’ Whether it’s gardening, birdwatching, joining a choir, or walking with friends, the focus should be on what brings you joy.
So, even if saunas and cold swims aren’t essential for health, they may still offer something positive. But here’s the thought-provoking question: Are we overestimating their health benefits, or is there more to uncover? What’s your take? Do you swear by saunas or cold plunges, or do you think the hype is overblown? Let’s discuss in the comments!
