Extreme Wellness Institute

BackgroundPassive heat therapies have been reported to have similar effects on the cardiovascular system as exercise. Studies supporting these findings in healthy populations have predominantly been done with men using warm water immersions or traditional saunas, rather than newer infrared-based saunas. ObjectiveTo explore short-term thermal and cardiovascular responses in women using an infrared sauna as compared to moderate-intensity exercise. Study designRandomized controlled crossover trial with balanced allocations. SettingBrisbane, Australia (August 2019 - March 2020) ParticipantsTen healthy women (36 ± 9 years) Interventions45 min of resting, infrared sauna or indoor bicycling Primary outcome measurestympanic/skin temperatures; respiratory rate; blood pressure; arterial stiffness; heart rate variability ResultsTympanic temperatures were elevated during infrared sauna as compared to both control (mean diff = +1.05 oC ± SEM 0.12 oC, 95% C.I.: 0.73 – 1.36, p < 0.0005) and exercise (mean diff = +0.79 oC ± SEM 0.12 oC, 95% C.I.: 0.49 – 1.08, p < 0.0005). Respiratory rates were higher during exercise as compared to both control (mean diff = +7.66 ± SEM 1.37, 95% C.I.: 4.09 – 11.23, p < 0.0005) and infrared sauna (mean diff = +6.66 ± SEM 1.33, 95% C.I.: 3.20 – 10.11, p < 0.0005). No significant differences in non-invasive measures of blood pressure, arterial stiffness or heart rate variability were detected between any of the interventions. ConclusionsThese findings suggest the physiological effects of infrared sauna bathing are underpinned by thermoregulatory-induced responses, more so than exercise-mimetic cardiorespiratory or cardiovascular activations.

Enveloped viruses such as SAR-CoV-2 are sensitive to temperature and are destroyed by temperatures tolerable to humans. All mammals use fever to deal with infections and heat has been used throughout human history in the form of hot springs, saunas, hammams, steam-rooms, sweat-lodges, steam inhalations, hot mud and poultices to prevent and treat respiratory infections and enhance health and wellbeing. This paper reviews the evidence for using heat to treat and prevent viral infections and discusses potential cellular, physiological and psychological mechanisms of action. In the initial phase of infection, heat applied to the upper airways can support the immune system’s first line of defence by supporting muco-ciliary clearance and inhibiting or deactivating virions in the place where they first lodge. This may be further enhanced by the inhalation of steam containing essential oils with anti-viral, mucolytic and anxiolytic properties. Heat applied to the whole body can further support the immune system’s second line of defence by mimicking fever and activating innate and acquired immune defences and building physiological resilience. Heat-based treatments also offer psychological benefits by directing focus on positive action, enhancing relaxation and sleep, inducing 'forced-mindfulness', and invoking the power of positive thinking and remembered wellness. Heat is a cheap, convenient and widely accessible therapeutic modality and while no clinical protocols exist for using heat to treat COVID-19, protocols that draw from traditional practices and consider contraindications, adverse effects and infection control measures could be developed and implemented rapidly and inexpensively on a wide scale. While there are significant challenges in implementing heat-based therapies during the current pandemic, these therapies present an opportunity to integrate natural medicine, conventional medicine and traditional wellness practices, and support the wellbeing of both patients and medical staff, while building community resilience and reducing the likelihood and impact of future pandemics.