FactSentinel

Colds are caused by viruses, most commonly rhinoviruses, and infection requires exposure to the virus itself. Simply being cold or going outside without a jacket does not introduce a pathogen into the body, so it cannot directly cause a cold. The common cold spreads through respiratory droplets, contaminated surfaces, or close contact with an infected person, none of which are related to ambient temperature exposure on their own.

The persistence of this myth likely stems from the fact that cold and flu season coincides with winter months. However, the reason illness spreads more during colder seasons has more to do with human behavior than temperature itself. People spend more time indoors in close proximity to one another during cold weather, which increases the likelihood of virus transmission. Additionally, indoor heating can dry out nasal passages, potentially making it slightly easier for viruses to take hold, and some research suggests cold, dry air may affect immune response in the respiratory tract in minor ways. Still, these factors are indirect and require actual exposure to a virus to result in illness.

A common misconception is that lowering body temperature weakens the immune system enough to spontaneously trigger illness. While extreme cold exposure can stress the body, healthy individuals do not develop colds simply from chilly weather without viral exposure. The scientific consensus remains clear: viral transmission, not temperature or clothing choices, is the primary driver of common cold infections.