Sauna, Cold Plunge, & Immune System Benefits

Cold and flu season in the winter intersects with allergy season in the spring, giving your immune system a seasonal workout. The reality is that colds and allergies don’t always abide by the seasons and can strike all year long. Sauna and cold plunge, or contrast therapy boasts numerous benefits, but what’s the impact on your immune system? Does sauna help allergies? Is it good to cold plunge when you’re sick? Read on to get answers to these questions and see how you can use the sauna and cold plunge to build your reserves.

My name is Christine Krall, and as a Naturopathic doctor, I’ve used several immune supportive strategies with patients. It ranges from herbal medicine, to nutrition, to at-home hydrotherapy techniques (which I’ll get into later).

Immune System and Inflammation

The immune system plays a major role in the body’s inflammatory response, which characterizes most diseases. The inflammatory process involves chemicals from the immune system called cytokines. Immune system disorders include allergies, infections, autoimmunity, and cancer, controlled by inflammatory mechanisms. Therefore, therapies that decrease inflammation – like sauna and cold plunge – can have a big impact on many diseases. We’ll focus mainly on allergies and infections.

There are up to 150 known autoimmune diseases affecting 8% of the US population. Autoimmunity means your immune system is overactive and attacks a certain part of your body. This causes inflammation and dysfunction. Contrast therapy helps autoimmune joint conditions like rheumatoid arthritis (RA) and ankylosing spondylitis [1,2,3]. Studies are needed for other autoimmune conditions.

Cancer develops when the immune system fails to flag and eliminate cancer cells. Chronic inflammation is thought to play an underlying role [4]. There are not enough studies on cancer and sauna to draw conclusions. Hyperthermia, which involves heating tumor tissue with a device, is used along with chemotherapy or radiation to enhance tumor-killing effects [5].

Allergies and Sauna

Allergy sufferers are tortured when their nemesis appears – pollen, leaf mold, dust – it’s hard to escape. Allergic rhinitis is an immune response in the nasal passages creating inflammation. A stuffy or runny nose, itchy and watery eyes, sneezing, shortness of breath, asthma, and fatigue can all be part of this exhausting experience.

So why does an allergen wreak havoc in allergy sufferers, but not in healthy people? Interestingly enough, it is thought to be an abnormal relationship between the immune system and nervous system. Sympathetic nervous system function is lower in people with allergic rhinitis. This causes nasal congestion and decreased air flow through nasal passages. The cool thing is that sauna activates the sympathetic nervous system, giving relief to allergy sufferers [6].

A study on people with allergic rhinitis showed that sauna therapy increased nasal airflow and lung function. Participants received 30 minutes of sauna therapy (broken up by several rest breaks) 3 days a week for 6 weeks. The sauna can help balance the sympathetic nervous system which impacts immune function [6].

Sauna and Cold Plunge to Prevent Colds and Respiratory Infections

How Does It Work?

Heat promotes your immune defense mechanisms against infections. Your temperature rises when you’re in the sauna by 1-3 ℃ (1.8-5.4 ℉), depending on sauna temperature [7]. This induced fever mimics your own body’s fever response to infection [8]. Heat stimulates heat shock proteins, which help the immune system fight infection [9]. Heat stress can directly inhibit pathogens, stimulate the immune system, and dampen inflammation (which causes tissue damage). Immune system benefits are further enhanced by alternating heat with cold [8].

Just one sauna session increases white blood cells involved in fighting infections. However, a series of sauna bathing is better for improving the immune response [10,11]. Similar immune effects were seen in cold water swimmers. White blood cells were higher in regular swimmers versus swimmers that were not cold-acclimated [12]. Regular winter swimmers have 40% fewer upper respiratory tract infections [13].

The Common Cold, COVID, and Pneumonia

A 6-month study showed that regular sauna bathing can decrease the incidence of the common cold [14]. During the pandemic, several papers proposed using contrast therapy for prevention and treatment of mild to moderate cases of COVID-19. Coronavirus as well as influenza (flu virus) and rhinoviruses (common cold virus) are particularly sensitive to heat [8,15,16]. A compelling statistic is that Finland and Estonia, countries that have an active sauna culture, had a lower number of cases and deaths from COVID-19 compared to the European average [16].

A reduced risk of pneumonia was seen in regular sauna bathers. Pneumonia is an inflammatory lung infection caused by bacteria and viruses. Frequent sauna bathing of 2 times or more weekly was associated with decreased risk versus people who had only 1 sauna per week or less. One of the ways sauna may improve lung function is by reducing oxidative stress (which causes cellular damage) [17]. The heat from the sauna may also have direct effects on the lung tissue improving lung function and reducing symptoms of lung disease [18].

Is It Good to Sauna or Cold Plunge When You’re Sick?

Some studies don’t recommend saunas when you’re sick, especially if you have a fever [19,20,21]. Other sources suggest that sauna and cold plunges may offer temporary symptom relief. According to Dr. Susanna Soberg, a cold water immersion researcher, you shouldn’t cold plunge when you have a cold. It might provide immediate relief for your symptoms, but that’s temporary and distracts from fighting the cold virus. Bottom line – contrast therapy is not an immediate cure for the common cold but may offer symptom relief.

Out of consideration for others, you probably don’t want to show up at the community sauna with a cold or flu. If you have a sauna at home – great. An at-home naturopathic therapy for colds and congestion is the “Wet Sock Treatment”. Sounds silly, but don’t knock it til you try it! My colleague Dr. Alicia Cole has a great explanation and how to video here. Even hot baths or contrasting hot and cold showers can help [22]. One study showed that ending showers on cold resulted in fewer absences from work due to sickness [23].

Can Kids Sauna to Prevent Colds?

This is a controversial topic. Finnish sauna culture includes children in the experience [24,25]. Children’s temperature regulating abilities are not fully developed, and most places don’t recommend it [26]. Sauna House’s policy is adults 18 and up only, but teenagers 14 and older are allowed if accompanied by a legal guardian.

Take Home Message

Regularly partaking in Sauna House’s Hot-Cold-Relax regimen is a proactive way to keep your immune system defenses up and inflammation in check. Especially if you’re a parent or teacher exposed to the kid’s latest germs. The old adage makes sense: an ounce of prevention is worth a pound of cure.

Citing our sources:

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2. Oosterveld FG, Rasker JJ, Floors M, et al. Infrared sauna in patients with rheumatoid arthritis and ankylosing spondylitis. A pilot study showing good tolerance, short-term improvement of pain and stiffness, and a trend towards long-term beneficial effects. Clinical rheumatology. 2009;28(1):29-34.
3. Peres D, Prati C, Mourot L, Demartino AM, Sagawa Y, Jr., Tordi N. Effects of an Exercise Program and Cold-Water Immersion Recovery in Patients with Rheumatoid Arthritis (RA): Feasibility Study. International journal of environmental research and public health. 2023;20(12).
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