Chilly Weather Can Lead to Common Cold

common cold

It turns out mother was right – at least in this case. Decades of children have been encouraged to bundle up in chilly winter weather to avoid catching a cold. Even though the common cold is a virus, it turns out that poor protection in chilly weather can lead to catching the common cold.

New research shows that catching a chill can thwart the body’s ability to fight off a cold. Researchers at Yale University have shown that exposure to cold temperatures does inhibit the virus-fighting immune system cells in the nose and allow the cold virus to thrive and spread more easily.

The research study, results of which are published in the Proceedings of the National Academy of Sciences, focused on rhinoviruses, the main group of viruses that cause the common cold. The Yale team study found that rhinoviruses can reproduce more efficiently at temperatures slightly lower than body temperature, i.e. below the normal 98.6 degrees Fahrenheit.

The team used mice for their common cold virus research. The results showed that when a rhinovirus invaded warmer nose cells, they set off an immune response in the body. The subject (or mouse, in this case) released more interferons, the proteins a body produces that “interfere” with the spread of a virus by essentially warning the subject’s healthy cells of its presence.

So what happens in cold winter temperatures? The researchers found that the cell warning system in nasal cavities was less efficient in cooler temperatures. This reduced body defense activity leaves noses streaming and allows the cold virus to spread more rapidly.

According to the U.S. Centers for Disease Control and Prevention (CDC), rhinoviruses and other viruses that cause colds can spread from those infected to other people through the air and close personal contact. People also get infected when they come in contact with snot, coughs or other respiratory secretions from someone who is infected. This contact can happen by shaking hands with a cold sufferer, or touching a light switch, bannister or doorknob that someone with a virus and unclean hands used and then touching ones eyes, mouth, or nose.

The CDC Web site recommends protecting oneself against rhinoviruses, the most common cold virus, by washing hands often with soap and water for at least 20 seconds or using a hand sanitizer. In addition, they encourage people to avoid touching any unwashed hands to one’s eyes, nose or mouth and stay away from those who may be sick. The Yale research team also suggests keeping one’s nose warm and avoiding cold air if one is infected.

The study’s authors noted how intriguing it was for them to consider the possibility that inhaling air in chilly weather can actually lead to lowering someone’s resistance to the common cold infections because it lowers the temperature of the cells lining the nasal cavity. They pointed out that the rhinovirus research gave credence to the “popular but controversial idea that exposure to cool weather conditions can increase susceptibility to common colds.”

By Dyanne Weiss

Sources:
PNAS (Proceedings of the National Academy of the Sciences)
Los Angeles Times
BBC
U.S. Centers for Disease Control and Prevention

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