What’s actually getting you sick when it’s cold out: doctor

It’s OK to brush off this advice.

One piece of “conventional wisdom” has echoed through households for generations, threatening those just trying to rush out the door — “Don’t go outside with wet hair, otherwise you’ll catch a cold!”

With cold and flu season well underway, this old wives’ tale may be ringing in your ears. But one internal medicine physician puts a damper on the lore, noting that there’s no scientific evidence that stepping out with damp locks on a brisk day will spark the sneezin’.

“The belief that you can catch a cold by going outside with wet hair is a myth,” Dr. Christopher Choi, a board-certified internist in Las Vegas, told The Post. 

“Wet hair does not directly have any bearing on catching a cold,” he explained. “A cold is caused by viruses, typically rhinovirus.” 

Rhinoviruses are considered the primary cause of the common cold, estimated to be responsible for 50% to 70% of cases.

The two primary modes of transmission for rhinoviruses, according to Choi, are “coming into contact with individuals infected with a cold who coughs and the other individual inhales the droplet, or by touching a surface infected with virus, which can live for hours, and then touching your face.”

Well, that’s one myth busted. But then why is it that — anecdotally — some people are adamant that they do seem to get the sniffles whenever they dismiss this superstition?

“Even though wet hair doesn’t directly cause colds, it can potentially contribute to body temperature dropping slightly, which could minimally contribute to catching cold,” Choi shared. 

Still, the biggest culprit is most likely the weather and not your head, especially since “there is some evidence that the rhinovirus multiplies better in cold weather,” Choi said. 

Plus, chilly temperatures are likely to weaken your immune system, making you more susceptible to infection.

And when you’re exposed to cold weather, the blood vessels in your nose constrict.

That means you have decreased protection against rhinoviruses because “the typical route of transmission is the nasal passages,” Choi said.

How to protect yourself from catching a cold

• Wash your hands 
• Avoid touching your face
• Stay away from sick people 
• Stay warm
• Clean and disinfect frequently touched surfaces