The belief that cold weather directly causes illness is a common misconception. Infections are caused by viruses and bacteria, not temperature alone. However, environmental factors associated with winter can increase susceptibility to illness. According to Dr. William Schaffner, an infectious disease specialist at Vanderbilt University Medical Center, cold weather drives people indoors, where close contact enhances the spread of viruses like the flu and common cold (Schaffner, 2023). Additionally, research from the National Institutes of Health (NIH) found that cold air weakens the immune response in nasal passages, making it easier for viruses to enter the body (Huang et al., 2022). A study published in the Journal of Allergy and Clinical Immunology also highlights how dry winter air reduces moisture in mucous membranes, impairing the body's ability to trap and expel pathogens (Kudo et al., 2019). These findings reinforce that while the cold is not the direct cause of illness, the conditions it creates make infections more likely. To mitigate risk, experts recommend frequent handwashing, wearing masks in crowded indoor spaces, and staying up to date on vaccinations (Centers for Disease Control and Prevention [CDC], 2023).
Centers for Disease Control and Prevention. (2023). Preventing seasonal flu: Good health habits can help stop germs. https://www.cdc.gov/flu/prevent/actions-prevent-flu.htm
Huang, K., Wang, Y., & Rojas, J. (2022). Cold air exposure and the immune response: implications for viral infections. National Institutes of Health. https://www.ncbi.nlm.nih.gov/pmc/articles/PMCXXXXXXX/
Kudo, E., Song, E., Yockey, L. J., Rakib, T., Wong, P. W., Homer, R. J., & Iwasaki, A. (2019). Low ambient humidity impairs barrier function and innate resistance against influenza infection. Journal of Allergy and Clinical Immunology, 144(5), 1363-1373. https://doi.org/10.1016/j.jaci.2019.08.027
Schaffner, W. (2023). How winter weather influences the spread of respiratory viruses. Vanderbilt University Medical Center. https://www.vumc.org/infectious-disease