Wet Hair

Going outside with wet hair will make you sick

Rachel has had long hair most of her life. Sometimes, it’s tempting not to dry all that hair, but she knows very well the looks of horror and the gasps of concern that will greet her if she heads out of the house without drying her long locks. Especially in the colder months, going outside with wet hair is considered a clear recipe for bringing on a cold or pneumonia or other health disaster. In a survey of parents bringing their children in to the emergency department because they had a cold, 41 percent of the parents believed that going out with wet hair in cold weather could cause a cold. But what’s the truth here? If you are too lazy or running too late to dry your hair, are you putting your health at risk?

The first thing to consider in answering these questions is just what it is that makes you sick. Having wet hair does not make you sick. Being cold or getting chilled because you have wet hair does not make you sick. It’s not even the combination of cold weather and wet hair that makes you sick. What makes you sick is when your body is infected with a virus or with bacteria. Developing a cold is the type of sickness that most people worry about when they go out with wet hair. If you learn one thing from this book, it should be that colds are caused by viruses, most often by viruses from the rhinovirus family. Without a virus sneaking into your nose or mouth or other wet parts, you are not going to get sick. You get sick because someone who is infected with a rhinovirus sneezes or coughs, sending tiny droplets of fluid and rhinovirus into the air around you or onto their hands or onto something else you might come in contact with. When you breathe in that air full of tiny virus-filled drops of fluid or when you shake their cough-contaminated hand, you get some of that virus into your nose or mouth. It’s that virus that makes you sick—not your wet hair!

The next question might be whether your wet hair makes you more likely to be infected by those viruses that cause our coughs and colds. Having wet hair does make you feel cooler, especially when the temperatures are low. Does that extra chill make you more susceptible to getting a cold? The science suggests that this is not the case. In study after study, scientists have tested this question by putting the viruses that cause colds directly into volunteers’ noses and then making them spend time in different kinds of conditions. They make some of the volunteers stay in chilled rooms or freezing conditions, while others are in warmer rooms. And they make some of the volunteers have wet hair, while others have dry hair. In these studies, volunteers exposed to the cold-causing viruses are no more likely to get infected by those viruses if they have wet hair or if they have dry hair. Whether or not they get cold or are in cold conditions doesn’t make any difference either. Getting chilled, whether from your hair or from the cold weather, does not make you susceptible to getting infected with a cold virus. There is no scientific evidence that getting cold will cause your cold.

For those of you who are still not convinced, there may be one piece of evidence in your favor. There was a study where people who had their feet chilled were more likely to report cold symptoms. Does this mean that you might notice more cold symptoms if your feet are cold than if your head is chilled from your wet hair? Maybe. That study has not been done. But, even here, the important thing to remember is that there is still no support for the chilled feet causing the cold symptoms. You may just notice your symptoms more because you have cold feet. Some exports hypothesize that having a very cold part of the body causes a reflex in which you have less blood flow to your nose and upper airways, and that this somehow inhibits your body’s defenses, converting a viral infection that you didn’t really notice into one that is causing you symptoms like a stuffy nose. But this hypothesis has never been proven. It’s just as likely that when you have had really cold feet from your wet boots or a really cold head from your wet hair, you get worried about whether you are going to get sick and so you notice your sniffles right away.

The next time your mother scolds you about your wet hair, you can explain about the rhinoviruses that cause colds and the volunteers who spent all that time in the cold with wet hair and viruses stuck in their noses. Or, you can just run out the door really fast!