From Libby Richards, Purdue University
Many of us have heard: “Don’t go outside without a coat; you will catch a cold. ”
That is not completly correct. As with many things, reality is more complicated. Here’s the difference: common cold isn’t why you have a cold. But it is true that cold weather makes it easier to catch cold or flu. It’s too early to say how the weather will affect the COVID-19 virus, but scientists are starting to believe that it behaves differently from the cold and flu viruses.
As an Associate Professor of Nursing with a background in public health, I am constantly asked about this. Here’s a look at what is actually happening.
Many viruses, including rhinovirus – the common culprit in colds – and influenza, stay infectious longer and multiply faster in colder temperatures. Therefore, these viruses spread more easily in winter. Wearing a thick coat doesn’t necessarily make a difference.
Virus transmission is easier when it is cold
In particular, cold weather can alter the outer membrane of the influenza virus; it makes the membrane stronger and more rubbery. Scientists believe the rubbery coating makes it easier for the virus to be transmitted from person to person.
It’s not just cold winter air that is causing a problem. Air that is dry as well as cold has been linked to outbreaks of flu. A study by the National Institutes of Health suggests that dry winter air helps the influenza virus stay infectious longer.
How your immune system reacts in cold weather is also of great importance. Inhaling cold air can adversely affect the immune response in your airways, making it easier for viruses to lodge. This is why it can be helpful to wear a scarf over your nose and mouth.
Also, most people get less sunlight in winter. This is a problem because the sun is an important source of vitamin D, which is essential for immune system health. Physical activity, another factor, also tends to decrease in winter. In snow or ice conditions, people are three times more likely to delay training.
Instead, people spend more time indoors. This usually means closer contact with others, which leads to the spread of the disease. Respiratory viruses generally spread within a six foot radius of an infected person. If you are indoors, there is a very good chance that they are closer together than six feet.
In addition, cold weather dries out your eyes and the mucous membranes in your nose and throat. Because viruses that cause colds and flu are usually inhaled, the virus can more easily attach itself to these compromised, parched passages.
What you can do
While the bottom line is that the wet and cold won’t make you sick, there are strategies to prevent illness year-round.
- Wash your hands often.
- Avoid touching your face, which people do between nine and 23 times an hour.
- Drink enough; Eight glasses of water a day is a good goal, but this can be more or less depending on the lifestyle and size of the person.
- Eat a balanced diet. Dark green leafy vegetables are rich in vitamins that support the immune system. Eggs, fortified milk, salmon and tuna contain vitamin D.
- Stay physically active even in winter.
- Clean the hard, touch-sensitive surfaces in your home frequently.
- If your nose or throat gets dry in winter, consider using a humidifier.
- Get the flu vaccine.
And one more important thing this year, when it is your turn to make sure you get the COVID-19 vaccine.
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Libby Richards, Associate Professor of Nursing, Purdue University
This article is republished by The Conversation under a Creative Commons license. Read the original article.