The Role of Temperature in COVID-19 Disease Severity and Transmission Rates

Abstract

Air temperature and body temperature may influence COVID-19 disease severity and transmission rates. In vitro data indicate that SARS-CoV-2 loses infectivity at normal core body temperature (37°C); however, small reductions in temperature proximate to 37°C may result in substantially increased viral stability. If these results are representative of viral decay rates in vivo, then cooler temperatures in the body may enable more rapid viral growth. Breathing cool air—even as warm as 25°C—cools upper respiratory tract (URT) surfaces to several degrees below body temperature, and these lower temperatures may make the URT exceptionally conducive to SARS-CoV-2 replication. Increased URT viral load may enable more effective transmission. Additionally, because SARS-CoV-2 infection may frequently begin in the URT before spreading through the body, an increased rate of viral replication in the URT early in the disease course may result in more rapid progression of disease, potentially causing more severe adverse outcomes. Core body temperature may also be a factor in disease severity, as lower core body temperatures may enable more rapid viral growth. The significance of air temperature and body temperature to disease severity and transmission rates may inform preventative measures and post-exposure prophylaxis treatments for COVID-19.

The effect of climate on the spread of the COVID-19 pandemic: A review of findings, and statistical and modelling techniques

“…The in vitro stability of SARS-CoV-2 experiments has shown that the virus is highly stable at 4 C but is sensitive to heat (Chin et al, 2020) and SARS-CoV-2 loses infectivity at normal core body temperature (37 C). However, small reductions at temperatures close to 37 C may substantially increase its viral stability (Kang, 2020). Many recent studies cited here have suggested a correlation between weather conditions and the COVID-19 pandemic in a similar way to other viral infections such as influenza.…”

Assessing the impact of temperature and humidity exposures during early infection stages on case-fatality of COVID-19: a modelling study in Europe

“…In addition to the evidence that low temperatures increased the stability and viability of the virus, inhalation of cold air at the initial virus exposure time, can make the upper airway more suitable for viral replication [34, 4], resulting in large viral load, and potentially more severe adverse outcomes. On the other hand, how the temperature that patients were exposed to after symptom onset affect immune responses is still unclear.…”

A Bioelectromagnetic Proposal Approaching the Complex Challenges of COVID-19

“…Nevertheless, the rising temperature could partially inactivate the viral infection by a long-lasting fever. Fever could alter the complex homeostatic regulation of the human body [219] [220].…”