Turning up the heat on COVID-19: heat as a therapeutic intervention

Abstract

<ns4:p>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.</ns4:p>

High fitness levels, frequent sauna bathing and risk of pneumonia in a cohort study: Are there potential implications for COVID‐19?

“…Regular sauna bathing has traditionally been used in Finland as a method of “hardening,” which means enhancing the body's resistance. Frequent sauna sessions reduce the risk of respiratory tract infections, such as common colds and pneumonia caused by viral and bacterial infections via (a) direct inhibition of pathogens; (b) boosting both the innate and adaptive arms of the immune system; (c) dampening of inflammatory responses; and (d) by having direct effects on lung tissue which include improvement in lung function and reduction in pulmonary congestion 28‐30 . Evidence suggests the adaptive responses produced by an ordinary sauna bath corresponds to that produced by moderate or high‐intensity PA 31…”

“…There is a wealth of evidence on the roles of regular PA and passive heat therapy as potent immune function stimuli, their ability to provide protection from viral infections and reduce inflammation. There is an ongoing debate that high levels of CRF levels may have protective effects on SARS CoV‐2 infection by attenuating the “cytokine storm syndrome.” 39 Furthermore, given that SARS CoV‐2 is highly sensitive to heat, 40 there are suggestions that passive heat therapies such as Finnish saunas could be used to ward off COVID‐19 or prevent severe disease 30 . Combining these two strategies may effectively reduce the risk of COVID‐19 or its severity, especially in the at‐risk groups like older adults and those with comorbidities.…”

Thermal inactivation scaling applied for SARS-CoV-2

“…A visit to the sauna has been suggested as treatment for Covid-19 patients (33), based on the prediction that the air temperatures may reach 85 C and the temperature in the trachea could reach up to 45 C despite the body perfusion (34). According to our model, however, t 4 (45 C) ¼ 7 h would be required to achieve 4 log10 damage, whereas the recommended time in sauna is $15 min.…”

A Potential Bioelectromagnetic Method to Slow Down the Progression and Prevent the Development of Ultimate Pulmonary Fibrosis by COVID-19

“…The SARS-CoV-2 virus is stable at a higher temperature, while other coronaviruses are thermosensitive. Heating the body in a wet environment (like a sauna) could be the solution by the inhalation of air with a high temperature (93). The complete inactivation of the virus needs a higher temperature (94); with a phase-transition-like phenomenon at 56°C, which is well over the physiological limit of the body temperature.…”