The primary cause of death from COVID-19 is acute respiratory distress syndrome (ARDS), a severe form of acute lung injury characterized by rapid breathing, shortness of breath, and a low blood oxygen level. The authors of recent review posit that moderate fever protects against ARDS in COVID-19.
The body’s fever response is a hallmark of infection and inflammation. An increase in core body temperature of a few degrees (no higher than ~102°F) is generally recognized as safe and improves survival from and resolution of many infections. For example, evidence indicates that people who take medications to reduce fever associated with influenza are 5 percent more likely to die. Conversely, extremely high fever in the setting of systemic inflammation is harmful. Notably, the fever response is diminished in older adults.
Fundamental to the fever response is a short-term accumulation of heat shock proteins (HSP), a class of proteins that play important roles in providing protection from lung injury. HSPs increase markedly with fever but require a “cool-down” period to maintain their effectiveness. In COVID-19 illness, the increase in HSPs is transient, lasting only about two hours after the onset of fever.
The authors of the review hypothesized that allowing patients with COVID-19 to experience brief (two hour) periods of fever, followed by administration of medications to reduce fever would maintain the highest levels of protective HSPs. They cautioned that their hypothesis must be tested in large, randomized clinical trials, however.
The authors also suggested that strategies that promote HSP activation may provide protection against COVID-19. Sauna use, in particular, induces long-term activation of HSPs and is associated with reduced risk of developing certain chronic or acute respiratory illnesses, such as pneumonia. Findings from large epidemiological studies indicate that men who used the sauna four to seven times per week were 41 percent less likely to develop pneumonia than men who used the sauna less often or not at all. Read more about sauna use in our overview article.
The science digest is a special email we send out just twice per month to members of our premium community. It covers in-depth science on familiar FoundMyFitness related topics.
If you're interested in trying out a few issues for free, enter your email below or click here to learn more about the benefits of premium membership here.