From coastal cold-plunge clubs in Cape Town to high-tech recovery hubs in Joburg and Durban, South Africa is in the middle of a massive thermal wellness movement.
What was once seen as an occasional hotel spa luxury or a post-gym afterthought has transformed into a cornerstone of local health culture, driven by sober socialising, biohacking, and longevity trends.
But beyond the post-workout sweat and deep relaxation lies serious clinical science, proving that deliberate heat exposure triggers powerful physiological adaptations that can transform your long-term cardiovascular, brain, and immune health.
Dr Tilla Muller, a GP at Mediclinic Hermanus, regularly advises patients on evidence-based wellness practices.
While acknowledging the promising research on saunas, she emphasises the importance of understanding both the benefits and limitations before incorporating saunas into your routine.
What happens under the heat
Whether sitting in a traditional wood-fired sauna reaching 70°C to 90°C, an infrared cabin set to 45°C to 60°C or a steam room of 30°C to 50°C, your body initiates a thermal balance strategy.
Vasodilation: Blood vessels expand drastically, reducing peripheral vascular resistance and lowering systemic blood pressure over time.
Cardiovascular output: Heart rate accelerates to 100- 150 beats per minute, directly mimicking the physiological strain and cellular benefits of moderate-intensity cardio.
Heat Shock Proteins (HSPs): Thermal stress unleashes specialised cellular repair proteins (such as HSP70) that refold damaged proteins, reduce oxidative stress and fight systemic inflammation.
Key health benefits
Medical research confirms that regular sauna use offers far more than superficial stress relief, triggering profound cellular and systemic adaptations across the body.
In a groundbreaking study that was published in 2015, over 2 300 middle-aged Finnish men were followed for more than 20 years. The results were striking: those who used saunas up to seven times a week had a 50% lower risk of fatal heart disease compared to those who only went once a week.
Cardiovascular health
- Expands plasma volume, lowers arterial stiffness and improves endothelial function.
- Associated with a 23% to 50% reduced risk of fatal cardiovascular events in frequent users.
Brain and longevity
- Triggers Brain-Derived Neurotrophic Factor (BDNF) and elevates cerebral blood flow.
- Linked to up to a 65% reduction in Alzheimer's and dementia risk.
Immune system
Simulates a mild fever response, rapidly mobilising white blood cells.
Significantly lowers serum C-reactive protein (CRP) and cuts the incidence of common respiratory infections.
Recovery and pain relief
Hyperthermic conditioning spikes human growth hormone release and accelerates muscle fibre repair.
Speeds up recovery from intense physical training and manages chronic joint or muscular pain.
"This increased blood flow during a sauna session is likely to deliver vital nutrients and oxygen to injured tissue while helping remove metabolic waste products that contribute to soreness,” says Dr Muller.
For South Africans managing high levels of daily lifestyle stress, thermal therapy offers a non-pharmacological route to lowering resting heart rate and regulating nervous system balance.
Traditional vs infrared
Traditional dry/wood-fired saunas: Dominating coastal plunge clubs and outdoor wellness spaces, these offer high ambient temperatures and rapid sweating, the exact conditions studied in Finnish longevity trials.
Infrared saunas and blankets: Highly popular in Johannesburg and Durban indoor recovery centers, using light panels to penetrate muscle tissue at manageable temperatures. This option is particularly favoured by athletes during humid summer months or heat-sensitive individuals.
Optimising your routine
While saunas offer benefits, they’re not for everyone, Muller cautions.
High heat and humidity can worsen conditions like asthma, may be unsafe in pregnancy and could be risky for people with low blood pressure, heart disease or a tendency to feel faint.
If you have a medical condition or take medication that affects your heart or blood pressure, check with a healthcare professional and keep sessions short, stay hydrated and listen to your body.
Meanwhile, Mark Meyerson, CEO of Revive, warns of the five hydration mistakes that sauna users often make.
Waiting until afterwards to hydrate: "Don't wait until you're thirsty. Arriving at a sauna already dehydrated makes it harder for your body to regulate temperature. Drink fluids consistently throughout the day and consider electrolytes if you've already been sweating through exercise or hot weather."
Heading straight from a workout into the sauna: "Combining an intense workout with a sauna significantly increases fluid and electrolyte losses. Allow your body time to cool down and begin hydrating before adding another heat challenge."
Assuming longer is better: "More time in the sauna doesn't necessarily mean greater benefits. Most experts recommend sessions of around 15 to 20 minutes, particularly for those new to sauna use."
Ignoring the signs your body is giving you: "Headaches, muscle cramps, dizziness, unusual fatigue or persistent thirst can all indicate that your body needs both fluids and electrolytes. Listen to your body and leave the sauna if you begin feeling unwell."
Forgetting recovery continues after you leave: Hydration doesn't end when the sauna session does. Continue replacing fluids afterwards and following heavier sweat sessions, consider replenishing electrolytes alongside water to support hydration.
"The goal isn't to make hydration complicated," adds Meyerson.
"It's simply to replace what your body loses. For many people enjoying regular sauna sessions, particularly after exercise or during summer, that means paying attention to electrolytes as well as water."
alyssia.birjalal@nationalmg.co.za