Gaby
We’ve all heard you can catch a cold if you go outside in winter with wet hair or without a coat. The truth is a little different: winter doesn’t just make you cold — it makes it easier to catch respiratory viruses.
Cold weather helps respiratory viruses spread, and lower temperatures have been linked to higher rates of COVID-19 and the flu, says Libby Richards, a nursing professor at Purdue University.
Richards says many viruses stay active longer and replicate faster in colder temperatures and lower humidity.
On top of that, cold weather drives us indoors and into closer contact with other people, which increases the risk of infection.
Richards points out that influenza and respiratory syncytial virus (RSV) show clear seasonality: they circulate more easily in the fall and winter.
Virus Transmission Is Easier in Cold Weather
Cold can change the outer membrane of the flu virus, making it harder and more rubbery. Scientists think that tougher coating helps the virus survive and transfer between people.
Dry air matters too. Dry conditions help the virus remain infectious for longer, according to Science Alert.
The way the immune system responds to cold air is important as well. Breathing cold air can weaken immune defenses in the respiratory tract, making it easier for viruses to take hold. That’s one reason covering your nose and mouth with a scarf can help: it warms the air before it reaches your lungs.
Most people also get less sunlight in winter, and sunlight is our main source of vitamin D, which supports immune health.
Physical activity tends to drop in colder months. Richards says people are three times more likely to skip exercise in winter, and spending more time indoors usually means closer contact with others — a common setup for viral spread.
Low temperatures and low humidity also dry out the eyes and the mucous membranes of the nose and throat. Viruses inhaled into the airway find it easier to attach to those dried-out surfaces.
How to Protect Yourself?
There are proven strategies to help protect your body from illness during winter:
- Wash your hands frequently.
- Avoid touching your face.
- Stay hydrated. Eight glasses of water a day is the optimal amount, but you can adjust it based on your lifestyle and body size.
- Maintain a balanced diet. Focus on dark leafy greens, eggs, and fatty fish like salmon, which are rich in omega-3s and vitamin D.
- Stay physically active.
- Get enough sleep.
- Wipe down frequently touched hard surfaces in your home.
- Use a humidifier if your nose or throat feels dry.
- Get your annual flu and COVID-19 vaccinations.
Follow these tips to help keep yourself healthy through the winter.
