UNC Healthy Heels

by: Emily Wheeler

Pretty much everyone who lives a sizable distance away from the equator has heard someone tell them that if they don’t bundle up before going out into the chilly weather, they’ll certainly get a cold. Some parents are obsessive about making sure their children look like Ralphie from “A Christmas Story” before they even let them consider going outside in the winter, and some well-educated adults still love to blame the outdoor temperature for their sniffles and coughs. We’ve had our share of cold weather and plenty of coughs and sneezes in Chapel Hill lately, but when we look into the facts, can the cold actually give you a cold?

Common cold symptoms include a sore throat that lasts for just one or two days, runny nose or nasal congestion, and a cough. Many different mild viruses, including the frequently mentioned rhinovirus, cause these symptoms. (Who knew that rhinos were the real cause of colds!? Sarcasm…) Viruses also cause the flu, which manifests symptoms similar to cold symptoms but with typically higher intensity and duration, and may also include fever, full-body achiness, and extreme exhaustion (1).

Because both cold and flu are caused by viruses, you cannot get a cold simply from being cold. Viral infections must enter the body through the eyes, nose, or mouth by contact with the virus itself, whether you’ve touched an infected desk at school or shared a drink with your significant other (1).

On the other hand, cold temperatures can indeed be an indirect cause of getting a cold. If you are out in the cold for an extended period of time without proper clothing, your overall body temperature will decrease to a point that suppresses the immune system. Cold temperatures can also cause blood vessels in the nose to constrict, leading to a dry nose and less mucus as a defense system in your sinus cavity. This combination of a suppressed immune system and decreased mucus, which is a first line of defense against viruses, can make you more susceptible to being infected by a virus with which you come into contact (2). However, exercising outside in the cold typically keeps the core body temperature from dropping too low, so don’t expect to see any hard-core runners staying indoors just because it feels like a refrigerator outside.

Cold temperatures may also stimulate mild asthma events in asthmatic individuals without causing a full-blown attack. Exposure to the cold may also actually stimulate your immune system to release more of the hormone norepinephrine, which can act as a decongestant and cause your nose to run (2). Many people mistake these symptoms for symptoms of an oncoming cold, and are quick to blame the weather for these naturally occurring events!

In fact, you might be more likely to catch a cold by staying indoors all the time in the winter because others around you are doing the same, creating a great environment for all of those cold-causing viruses to spread between several people in a limited amount of space.

The most effective ways to avoid getting a cold or the flu are not to bundle up or stay inside. Instead, you should wash your hands with warm water and soap often, and keep your hands away from your face! Certainly try to use hand sanitizer or wash your hands before you eat, put in contacts, or even rub your eyes.

As the evidence shows, the old saying that “the cold will give you a cold” turns out to be just a myth. Many sources say this assumption likely carries over from before medical knowledge had progressed enough to understand the immune system and the transmission of disease. People noticed that more people seemed to be sick during cold times of the year (the time we now like to call flu season), so they figured that the cold must be the culprit. People also used to think that swamp air caused malaria, when in fact it was the mosquitoes living near the swamps (2). Luckily, we now know that going out in the cold in shorts and a tee shirt might not give you a cold with coughs and sniffles, but we can’t change the fact that you’ll still look silly.

Enjoy this short video with great illustrations to hear more about other hypotheses that may explain more about the indirect relationship between getting sick, and being cold!