A closer look
Rhinoviruses and other upper respiratory infections are transmitted strictly through viral contact and absolutely not by simply walking outside without a jacket in the middle of winter, despite what generations of angry mothers have claimed. The only reason cold weather correlates with sickness is that people huddle together indoors with terrible ventilation, happily breathing each other's aerosolized germs in a nice, warm, enclosed environment. Stepping into freezing air with wet hair will certainly make you miserable and uncomfortable, but it physically cannot magically conjure a pathogenic virus out of thin air to infect your sinuses. We have spent centuries blaming the innocent winter weather for our illnesses when the real biological villain is just our own disgusting, germ-covered friends and family members. Your grandmother's medical advice was essentially just a superstitious myth meant to sell more knitwear
