Why an outdoor sauna is a great way to support your immune system and cardiovascular health

Did you know saunas can help protect us against invaders?

While our luxury Wildhut outdoor saunas are robustly built, we’re not suggesting you barricade yourself inside one on the off chance the Vikings reappear! We’re talking about viruses and pathogens that can invade the body and how regular sauna usage can help keep them at bay.

We listened to a fascinating episode of Steven Bartlett’s podcast, Diary of a CEO*, where Dr Roger Seheult threw some light on this important subject. As part of his exploration of the role of Vitamin D in our health and longevity, Dr Seheult made some observations about saunas and how they can help protect us that we’d like to share with you here.

(This is our layman’s interpretation, so please do check out the original podcast if you’d like to hear the expert version!)

How turning up the heat protects your health

Body temperature and our immune systems are closely linked. Here’s how…

Our immune system is made of up two types: the adaptive that kicks in to fight a specific disease and the innate which is always running in the background.  The innate immune system constantly patrols the body, a bit like a security guard, on the look-out for foreign cells and pathogens that can do us harm.

At the heart of this system is interferon, a type of signalling protein that is released by a cell when it is infected to ‘interfere’ with the virus and trigger other nearby cells to protect themselves and help prevent the virus from replicating.

This is where the heat part comes in. The production of interferon goes way up with a rise in body temperature, which is why we often get a fever when we are fighting a serious infection. As a bonus, viruses don’t replicate well at high temperatures either.

Why home saunas give us an advantage

When people spend time in a sauna it heats up the body and causes us to sweat, a bit like an induced fever state.

In the podcast, Dr Seheult mentions that in one study, raising body temperature to 38°C caused a tenfold increase in the production of interferon. Meanwhile, another study showed that high levels of interferon correlated with mild SARS COVID infection in patients, while people with low interferon levels had more severe COVID infections.

He also explains there is evidence from Finnish sauna experience that people who sauna four times a week or more are less likely to die from cardiovascular disease than people who only sauna once a week.

Adding a dash of contrast bathing brings benefits too

It can also be beneficial to do hot and cold therapies together, for example, by heating up the body in a sauna for twenty minutes, followed by a brief cold shower or cold plunge. This helps in two ways:

Firstly, the cold water causes our blood vessels to constrict so that when you’ve finished your sauna session you don’t lose as much heat through your blood vessels and you keep your body temperature higher for longer which promotes interferon production.

Secondly, the sudden constriction of the blood vessels causes white blood cells that cling to the walls of the blood vessels to be released into the blood stream so they can travel around the body fighting infection.

Relax while you take care of yourself

The joy of sauna is that it’s not only a delightful way to unwind and have the chance to reconnect with yourself, it’s also doing your health and wellbeing a power of good at the same time.

If learning about the health giving benefits of sauna bathing has inspired you to bring more balance, delight and self care into your everyday life, why not explore the idea of owning your own Wildhut sauna? Whether you're dreaming of a peaceful solo retreat or a space to connect with others, our beautifully crafted saunas are designed to nurture body, mind and soul. Discover the full Wildhut range and take the first step towards creating your very own sanctuary of heat, healing and hormonal harmony.

Top tip: If you’ve enjoyed this article, you might also like to take a look at our Unlock the Secrets to a Healthier Life with Sauna Bathing and Sauna: what’s love got to do with it? articles too.

* Podcast ref: DOAC (Diary of a CEO), 17 July 2025, ‘Vitamin D expert: the fastest way to dementia – and the dangerous lie you’ve been told about sunlight!’