Cold and Flu

Does cold weather make you sick?

 (Dirima)

Growing up, your mom may have warned you to stay out of the cold if you wanted to avoid getting sick. But you’ve probably dismissed that advice as an old wives’ tale. After all, viruses and bacteria are what make you sick—not the weather. Right?

Turns out, your mother may have been right all along. At least, that what the results of a new study seem to imply. (But here are 5 things your parents taught you that are wrong.)

Researchers from Sweden and Scotland collected over 20,000 nasal swabs over a 3-year period to detect respiratory illnesses. Then, they analyzed local weather data. The researchers discovered that outbreaks of respiratory infections like the flu and respiratory syncytial virus—a virus that causes cold-like symptoms—began during each year’s first low-humidity, below-freezing week. In other words, the winter chill kick-started flu season.

Viruses—like those that cause flu—travel in liquid particles, which survive better in dry, cold climates, the authors theorize. This type of air absorbs extra moisture, leaving the particles light enough to stay airborne. That means they’re more accessible for someone else to breathe in—and catch something from.

So yes, you are more likely to get sick when it’s cold out. But there are other reasons at play as well, says pulmonologist Gustavo Ferrer, M.D., author of Cough Cures and founder of Cleveland Clinic’s Cough Clinic in Miami. 

One factor? As air temperatures drop, your mucus secretions increase. As a result, you might have noticed yourself coughing, sneezing, and blowing your nose more over the past few weeks, even if you’re not actually sick. But if you are sick, mucus acts as a prime vehicle for virus transfer.

So if you sneeze and send droplets of mucus flying, you’re transmitting a greater number of virus particles into the air. And the cold, dry air of winter leaves the bugs more easily accessible to the next unlucky guy who breathes in that area.

That’s why it’s especially important to take measures to keep yourself safe when winter rolls around: Wash your hands, stay hydrated, and avoid close contact with sick people when you can. (These are the 4 best ways to prevent a cold.)

But your mom’s other piece of advice—bundling up to avoid sickness—might not be as helpful as she thought. When you’re warmer, you do produce less mucus, so you’re less likely to infect others, says Dr. Ferrer. When it comes to your own health, though, no piece of clothing can protect you—unless it’s literally covering your nose and mouth and preventing you from breathing any bugs in. (Follow these 26 ways to avoid getting sick this winter.)

Still, you don’t want to be the one guy who gets the whole office croaking. If you’re sick, make it your mission to avoid inflicting the same fate on others: Cough and sneeze in your elbow to prevent spraying your germs all over, says Dr. Ferrer. And don’t be afraid to take a sick day.

This article originally appeared on RodaleWellness.com.