Cold weather and wet hair won't make you sick. Here's what actually does.

Your mum was wrong. Going outside with wet hair in winter won't give you a cold, no matter how many times you heard it growing up.

Doctors have been saying this for years, but the myth persists. "There's no evidence or literature to suggest that," says Dr. Swapnil Patel, vice chair of medicine at Hackensack Meridian Jersey Shore University Medical Center. Yes, wet hair does lower your body temperature and make you feel miserable. Yes, cold air can constrict your blood vessels and temporarily worsen existing cold symptoms. But the cold itself doesn't cause infection.

If you catch a cold after a winter walk, it's not the weather. It's a virus.

What Actually Spreads Colds

Colds spread through contact with infected people — specifically, their respiratory droplets. When someone sneezes or coughs near you, you're breathing in the virus. When you touch your eyes or mouth with unwashed hands after touching a contaminated surface, you're giving the virus a direct route inside.

This is why prevention is so straightforward, even if it feels tedious. Wash your hands regularly with warm water and soap. Wear a mask around people who are visibly ill. Keep some distance from coughing colleagues. These aren't glamorous interventions, but they work because they interrupt the actual transmission chain.

What also helps: keeping your immune system in decent shape. Regular exercise, adequate sleep, and eating reasonably well don't make you invincible, but they do give your body better tools to fight off a virus if you do encounter one. A strong immune system won't prevent exposure, but it can mean the difference between a three-day inconvenience and a two-week ordeal.

The real lesson here isn't just that your mum was mistaken. It's that the actual mechanics of how illness spreads are simpler and more actionable than we often think. You can't control the weather. You can control whether you wash your hands before touching your face.