For years now, we have heard our mothers and grandmothers warn about catching flu from being outside in the cold weather, especially without a hat or jacket. How much truth is there in the common belief that you can catch a cold by being outside in the chilly weather? What, then, about the Alaskans and people living in Siberia, who live year-long above the Arctic Circle and spend each day outside in the cold weather? Judging by the same belief, then people living around the equator should not be getting any colds. Let us explore the truth about whether or not you get the flu from being out in the cold.
Is There A Connection Between Cold Weather and the Flu?
For years and years, the myth has been going around that going out in the cold weather will make you sick, catch a cold, or come down with the flu. However, while we have all grown up hearing this myth being reinforced by our mothers and grandmothers, then why is it that the peak flu season falls during the winter?
The fact is that no, the cold weather does not make you sick. Flu or influenza is an infectious disease and germs make you fall ill, not the cold weather. In order to catch the flu, you need to be infected with the influenza virus, and in order to catch a cold, you need to come in contact with rhinoviruses.(1)(2)
However, the reason it seems like you come down with the flu during the winter season is that the influenza virus tends to peak in winter.
Nevertheless, the cold weather is not the only reason why you tend to catch the flu. There is also a connection between getting sick and feeling chilled in the winters.(3) The reason behind this is that cold air contributes to other conditions that make us more susceptible to falling ill.
Your Immune System and Viruses
The cold weather is actually ideal for many viruses to spread. For example, research has found that rhinovirus (which causes the common cold) can replicate better and faster at cooler temperatures, especially in conditions that are present in the nose (temperature of 33-35o Celsius) as compared to the body’s core temperature, which ranges between 33-37o Celsius.(4)
The cold weather negatively affects the immune system, making it challenging for the body to fight against potential bacteria and viruses. Some of the reasons behind this may include:
Lower Levels Of Vitamin D In The Winters: During the winter season, most people do not get sufficient exposure to vitamin D due to lower sun exposure. Research by the Feinstein Institute for Medical Research in New York found that vitamin D is responsible for maintaining the immune system.(5) Low exposure to vitamin D, thus, causes the immune system to stop functioning optimally.
Narrowing of the Blood Vessel: Breathing in dry and cold air leads to the narrowing of the blood vessels in the upper respiratory tract. This is known as vasoconstriction. The body does so in an attempt to conserve heat. However, this prevents white blood cells from traveling to the mucous membrane, making it difficult for the body to fight against the invading bacteria or viruses.
Staying Cooped Up Indoors: In the winter months, people prefer to remain indoors rather than venturing out in the cold. Viruses are more prone to spreading from person to person when everyone is inside and close to one another.
The Yale University School of Medicine carried out a study in 2015 that discovered that the cells of the immune system initiate a more potent antiviral defense when they are at lung temperature, instead of the temperature in our nasal cavity.(6) This means that the body is not able to effectively fight the virus when the temperature in the nose and upper airways is lower than the lung temperature, due to the cold environment of winters.
Further studies carried out by the University of Arizona indicate that the influenza virus is able to thrive in cool and dry temperatures. However, studies by the US Department of Health and Human Services has also shown that influenza is also widespread in warm and humid climates.(7)
This indicates that other factors are also at play when it comes to determining the immune response of a person to the influenza virus. These may include changes in temperature or even the impact of light and dark cycles.
Nevertheless, the bottom line still established by all these studies is that cold weather or hot weather does not cause the flu. Weather and other factors weaken your immune system, diminishing your ability to fight off the flu.
Other Factors That Cause Flu or Illness
As mentioned above, there are many other factors in the winter season that weaken your immune system, leading to diseases. Some of these factors are looked at below.
Perhaps the most significant factor responsible for so many colds and the flu in the winter season is central heating. When it is cold outside, you prefer to remain indoors, where the temperature is warm. Central heating and the dry air associated with central heating makes it very easy for the flu and cold viruses to enter your dry nasal passages.
Even though dry indoor air, by itself, is not going to make you fall sick, but it plays a significant role in allowing aerosol droplets from a sneeze to thrive and survive.
In 2011, a research team at China’s Tianjin University came to the conclusion that students living in dorm rooms with poor indoor ventilation were catching more colds.(8) Similarly, another 2011 research at Virginia Tech University found that proper ventilation and high relative humidity indoors forces the influenza type A virus to become inactive.(9)
Perils of Staying Outside in the Winter
The winter months tend to have dry air. Dry winter air is associated with flu outbreaks. The National Institute of Health (NIH) states that dry winter air aids the survival and transmission of the flu virus.(10) Research by the National Institutes of Health has found that the coating or outer membrane of the flu virus becomes tougher when exposed to temperatures that are close to freezing. This makes the virus more active, more resilient, and it gets easily transmitted in the cold weather.(11)
Prevention from the Cold and Flu
Here are some tips on how to avoid falling sick with the flu or catching a cold during the winter season:
- Get plenty of sleep
- Take vitamin D supplements or increase the consumption of foods rich in vitamin D such as fatty fish, eggs, and mushrooms
- Stay well hydrated
- Wash your hands frequently, especially when you come from outside
- Use clean tissues for sneezing and coughing. If you don’t have a tissue handy, then use your elbow to sneeze or cough into rather than covering your face with your hands
- Avoid sharing utensils, crockery, drinks, and foods, with people who have the flu or a cold.
- If you have a fever, then it is best to stay at home for at least 24 hours after your fever subsides.
- Indulge in some form of physical activity every day for at least 10 to 15 minutes. Regular exercise boosts your immune system and speeds up your recovery from any illness.
- Avoid touching your face, especially with unwashed hands. This is one of the easiest ways for germs to enter your body.
Remember that influenza is one of the only respiratory viruses that can be prevented by vaccination. This is why it is so essential that you get your yearly flu shot.
5 Home Remedies To Get Rid of Flu or Cold
There’s no treatment for the flu except to battle it out. Here are some tried and tested home remedies that help you deal with the flu and make you feel slightly better as you wait out the virus:
- Hot Chicken Noodle Soup: The oldest home remedy to get rid of cold and flu is chicken noodle soup. This soup helps alleviate congestion as you have it steaming hot. Hot and steamy soup helps loosen the mucus, allowing the nose to run. This decreases the pressure on your sinuses, helping you feel better. The steam from the chicken noodle soup also helps with the irritation and dryness in the nose. Chicken noodle soup is also believed to have anti-inflammatory properties.(12)
- Take Vitamin C Supplements: Vitamin C is known to help boost your immune system. When taken at doses between 1-2000 milligrams per day, vitamin C supplements may reduce your cold by one entire day. However, trying to get vitamin C from orange juice is not going to be very useful. This is why taking supplements when you have a cold and flu is a better option.
- Have Tea With Honey: The health benefits of honey are well known. Drinking tea with honey mixed in it helps soothe the throat. Honey is also a powerful antioxidant that helps you feel better making it a useful home remedy. Having tea with honey also helps to keep you hydrated. Remember that hydration is an essential factor in overcoming the flu.(13)
- Take Zinc Supplements: Consuming at least 75 milligrams of zinc every day has found to reduce the length of the flu virus by an entire day.(14) Regular supplementation of zinc in the elderly is known to reduce the incidence of infections.(15)
- Use Steam: Taking steam is one of the easiest home remedies to get relief from congestion. It helps moisten the nasal passages and also helps drain the mucus. However, you need to be careful while taking steam as it may also cause burns. Even turning on the hot water in the bathroom and sitting inside with the door closed is beneficial.(16)
Cold weather does not cause the flu and the common cold. These illnesses are caused by viruses such as influenza (flu virus) and rhinovirus (cold virus). The weather, though, has a role in increasing a person’s risk of catching a virus and falling sick.
Research has shown that the flu and cold viruses can thrive and multiply rather rapidly when exposed to colder temperatures, which makes it easier for them to spread and infect other people. Staying indoors during the cold weather also increases the risk of more people getting infected with the virus. At the same time, cold weather lowers the body’s immune response, making it difficult for the body to fight off these viruses and bacteria.
By taking proper precautions and by following good hygiene, you will be able to protect yourself from the flu during the winter months.
- Who.int. (2020). Influenza (Seasonal). [online] Available at: https://www.who.int/news-room/fact-sheets/detail/influenza-(seasonal) [Accessed 28 Jan. 2020].
- Douglas Jr, R.G., Lindgren, K.M. and Couch, R.B., 1968. Exposure to cold environment and rhinovirus common cold: failure to demonstrate effect. New England Journal of Medicine, 279(14), pp.742-747.
- Cross, K.W., 1963. The effect of weather on winter epidemics. Postgraduate medical journal, 39(456), p.594.
- Jacobs, S.E., Lamson, D.M., George, K.S. and Walsh, T.J., 2013. Human rhinoviruses. Clinical microbiology reviews, 26(1), pp.135-162.
- Aranow, C. (2020). Vitamin D and the Immune System. [online] PubMed Central (PMC). Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3166406/#idm139736676964112title [Accessed 28 Jan. 2020].
- Foxman, E.F., Storer, J.A., Fitzgerald, M.E., Wasik, B.R., Hou, L., Zhao, H., Turner, P.E., Pyle, A.M. and Iwasaki, A., 2015. Temperature-dependent innate defense against the common cold virus limits viral replication at warm temperature in mouse airway cells. Proceedings of the National Academy of Sciences, 112(3), pp.827-832.
- Tamerius, J., Nelson, M.I., Zhou, S.Z., Viboud, C., Miller, M.A. and Alonso, W.J., 2011. Global influenza seasonality: reconciling patterns across temperate and tropical regions. Environmental health perspectives, 119(4), pp.439-445.
- Sun, Y., Wang, Z., Zhang, Y. and Sundell, J., 2011. In China, students in crowded dormitories with a low ventilation rate have more common colds: evidence for airborne transmission. PloS one, 6(11).
- Yang, W. and Marr, L.C., 2011. Dynamics of airborne influenza A viruses indoors and dependence on humidity. PloS one, 6(6).
- National Institutes of Health (NIH). (2020). Dry Air May Spur Flu Outbreaks. [online] Available at: http://www.nih.gov/researchmatters/march2010/03082010flu.htm [Accessed 28 Jan. 2020].
- National Institutes of Health (NIH). (2020). Flu Virus Fortified In Colder Weather. [online] Available at: https://www.nih.gov/news-events/nih-research-matters/flu-virus-fortified-colder-weather [Accessed 28 Jan. 2020].
- Marsh, S.B., 2019. Soup is a healthy choice; chicken noodle soup really does help cure a cold. Letters to the Editor [Dorothy Paulsen].
- Kumar, K.S., Bhowmik, D., Biswajit, C. and Chandira, M.R., 2010. Medicinal uses and health benefits of honey: an overview. J Chem Pharm Res, 2(1), pp.385-395.
Singh, M. and Das, R.R., 2013. Zinc for the common cold. Cochrane Database of Systematic Reviews, (6).
- Prasad, A.S., Beck, F.W., Bao, B., Fitzgerald, J.T., Snell, D.C., Steinberg, J.D. and Cardozo, L.J., 2007. Zinc supplementation decreases incidence of infections in the elderly: effect of zinc on generation of cytokines and oxidative stress. The American journal of clinical nutrition, 85(3), pp.837-844.
- Forstall, G.J., Macknin, M.L., Yen-Lieberman, B.R. and Medendorp, S.V., 1994. Effect of inhaling heated vapor on symptoms of the common cold. Jama, 271(14), pp.1109-1111.
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