“Cold weather causes colds”

It's a common belief that stepping out into chilly air or not bundling up enough will inevitably lead to a runny nose and a cough. This widespread misconception likely stems from the undeniable correlation between colder months and a surge in common cold cases. For centuries, before the advent of germ theory, it was a logical leap to assume that the environmental cold itself was the culprit, especially when sickness seemed to follow exposure to low temperatures. This idea became deeply ingrained in folk wisdom and parental warnings, passed down through generations.

However, scientific understanding has long since "busted" this myth. The common cold is not caused by cold weather, but by viruses, primarily rhinoviruses, which infect the upper respiratory tract. Exposure to cold temperatures does not directly cause these viral infections. Research has shown that even direct exposure to cold air or being chilled does not make a person more susceptible to catching a cold if they are not exposed to the virus itself. Your immune system is capable of functioning effectively even in cold environments, though some studies suggest cold air can subtly affect immune responses in the nose, potentially making it easier for viruses to take hold.

The reason this myth persists, and why we do indeed see more colds in winter, is not primarily because of the temperature, but because of human behavior during colder seasons. When temperatures drop, people tend to spend more time indoors, often in closer proximity to one another in schools, offices, and homes. This increased indoor crowding creates ideal conditions for respiratory viruses to spread easily from person to person through airborne droplets or contaminated surfaces. Additionally, some viruses, including rhinoviruses, can survive longer and even replicate more effectively in colder, drier air, which is common in winter. So, while you might feel a chill, it's the increased likelihood of encountering a virus indoors, rather than the cold weather itself, that makes you sick.