Buzz
Although you can catch a virus at any time of the year, winter seems to bring about a rise in sickness. Flu shots are typically administered in preparation for the seasonal spread, and anecdotally, you might hear people say they’ve 'caught something' or 'picked up a bug.'
We often attribute the spread of colds and the flu to cold weather driving people indoors, but could there be other factors at play? Or is it just that?
It's true that spending more time inside can bring us closer to others, increasing the chance of transmission. However, there are additional factors. According to the National Institutes of Health, the lipid (fatty) coating of influenza viruses becomes liquid at warmer temperatures, weakening their stability and spread. In cold weather, though, the lipid membrane stays intact, making the virus more resilient and persistent. Once it reaches the respiratory tract, the coating breaks down, allowing the infection to begin.
Viruses can thrive in cooler temperatures in several ways. Winter brings drier air, both indoors and outside, which can aid their spread. With less moisture in the air, viruses can travel longer distances and linger in the atmosphere without binding to water molecules. Additionally, reduced ventilation inside can result in stale air, making germs persist in the environment.
Could cold weather affect our immune systems? There’s some research suggesting that cold conditions might weaken our immune defense. A study in *The Journal of Allergy and Clinical Immunology* explored how colder temperatures could reduce immune activity in the nose, although the study was limited to just four subjects, and no definitive conclusions were reached. There's still no agreement on whether being cold directly impacts our immune system. While changing body temperatures might play a role in fighting illnesses, casual exposures like going outside with wet hair or wearing a T-shirt to get the mail probably aren't major causes of sickness.
While winter may raise your chances of catching an illness, the basic rules for staying healthy remain the same. Regular handwashing can reduce the spread of germs, as can disinfecting surfaces frequently. It's also important to avoid sharing eating utensils or drinking glasses with others. Vaccines can further reduce your risk of infection.
