With no cure for COVID-19, there’s much debate in the wellness industry about interventions which can strengthen the immune systems of those who want to take steps to avoid it, and also modalities that can potentially help support people with the virus. Sauna is one of those most widely discussed.

It’s worth noting that the initiation of global government shutdowns means many spas, thermal experiences and public bathing facilities have been closed, restricting accessibility to such therapies – but this article could provide many details to contemplate for when they do reopen. Meanwhile, in many European countries like Finland and Germany, where people have long believed in the benefits of heat, private saunas in houses are not uncommon.

Dr Marc Cohen, an integrative medicine expert; Risto Elomaa, president of the International Sauna Association (ISA); and Dr Karl-Ludwig Resch, head of the German Institute for Health Research, have all recently shared their views on saunas and coronavirus.

Cautionary tale
ISA represents sauna associations, companies and enthusiasts the world over (see SB18/3) and in a recent statement, which has been reviewed by medical experts for accuracy, its message is one of caution. “Even though viruses can be quickly destroyed by the heat in most sauna rooms (65-100˚C), coughing and sneezing in close proximity to other bathers can transfer a virus from one person to another before the heat has time to react.”

Cohen, who has a background as a medical doctor and a professor of health sciences and complementary medicine concurs. He emphasises the need for medicalised protocols, with rules about social distancing and procedures adapted from existing hospital regulations, to be implemented when spas do reopen.

But can heat help protect us against coronavirus? Yes says the ISA, but only from a preventative standpoint where sauna remains an integral part of a healthy lifestyle that includes exercise, smart eating and sleeping habits combined with social interaction. Elomaa adds a warning: “If you’re sick with the coronavirus or any respiratory illness, you should refrain from using the sauna. It will not directly contribute to healing the disease and the body’s reaction to heat can put a strain on an already stressed body, which can lead to serious health issues.”

Resch thinks along similar lines. “As long as there is no drug that effectively acts directly against the virus, all therapeutic approaches are limited to supporting the body’s immune system and hoping it will somehow get to grips with the invader,” he says. “You should also take particular care if you are already experiencing symptoms of respiratory tract infection or even have a slight fever: the body may have a difficult time with a ‘healthy’ counter-regulation, especially if it has not already learned to deal positively with high temperature stimuli by taking sauna baths regularly.”

However, Cohen believes heat-stress could potentially help prevent and treat COVID-19 and is in the process of completing an academic paper collating scientific evidence from previous studies to demonstrate this. “I’m frustrated and concerned there’s no positive health information coming from the authorities on what to do once you have the virus,” he says. “It’s all focused on washing your hands and self-isolating, nothing about how to boost your immunity, clear the virus from your upper airways or about the effective use of heat, sunlight or essential oils. Instead, people who are infected are told to just ‘hunker down and wait for a vaccine’.”

How can sauna help?

Cohen explains that there’s plenty of medical evidence to show that people who use saunas regularly get less viral infections. Treating the common cold and other respiratory viruses with heat also leads to lower-incidence rates, as shown by 2017 research by SK Kunutsor at the University of Bristol, UK (see above). Although this study doesn’t target people aged 70 and over and black and ethnic minorities who have been identified as high risk and potential high risk groups for contracting coronavirus.

He also contends that humans have been using heat – such as saunas and sweat lodges – for prevention and cure, throughout history. This approach essentially uses the sauna to outsource the work of the immune system to simulate a fever, meaning less physical exhaustion for the body than a fever driven by infection. In addition, humans can tolerate high temperatures in saunas in which the virus cannot survive and at the same time heat-stress activates, heightens and stimulates the immune system, while inhibiting viral replication.

Resch says coronavirus, like the flu, first multiply in the nose, throat and upper respiratory tract – areas which may be reached effectively with external heat. “Sauna is a real secret weapon,” he says. “You should take a sauna bath as often as possible (daily!) and for as long as possible. The latter works best if the temperature is set relatively low: 60-70˚C is probably sufficient. By increasing temperature, the effect may work further into the upper respiratory tract, but possible and well-tolerated duration of exposure decreases. 

“Many aspects of the current pandemic are still in the starting blocks of scientific research, but what has been scientifically proven is that taking sauna baths regularly is a highly-efficient means of training the body’s own immune system,” he adds referencing three particular studies (see p79). “This may significantly increase the chances of fending off an infection (at least if the dose of virus you have been exposed to is not too high). If you should become infected, it might be much milder and the course of the illness much shorter without life-threatening crisis.”

Cohen explains: “We need more evidence before we can be sure of the effects of heat in combating coronavirus, because that research has not yet been done, as COVID-19 is a new virus, but there’s a huge line of evolutionary and historical evidence from humans, as well as epidemiological and laboratory evidence that consistently point to the therapeutic application of heat having a positive effect in dealing with respiratory viruses.”

The belief is that inhaling warm, moist air, such as over a bowl of hot water, or dry salt inhalation can also potentially help.

Psychological benefits
Experts think that because the body goes through a physiological state of hyper-arousal in a sauna, it’s important to balance this with hyper-relaxation. Furthermore, sauna can help alleviate psychological symptoms when coping with coronavirus, helping people feel more in control of symptoms and allowing time for dedicated rest.

Resch says: “A sauna bath stimulates the body, mind and soul, gives us a nice break during these chaotic times and boosts our inner metabolism.”

Cohen adds: “Around 80 per cent of people will get this virus, they may be asymptomatic or get milder symptoms, but they’re all panicking. If you’re in fight or flight mode your body is not going to be using energy on healing from coronavirus.

“I actually think there’s a huge scope for including saunas, steamrooms and hot bathing into hospitals, care homes and public facilities. I really think that when we come out of this, the health system could be much more integrated with conventional medicine and wellness practices.”