Is anyone sick of being sick? I certainly am.

Little-Man Strovas battled colds, ear infections, eye infections (notice how these are all plural), pneumonia, and the flu this winter. Poor kid is only a year old.

The rest of us were staying somewhat healthy until we picked up a nasty flu virus. We all suffered the full spectrum of flu symptoms and were miserable for 10 days. It took us two weeks to recover and my cough persisted for over a month.

Now, schools in our area are shutting down due to high rates of illness-related absences. Three schools shut down for two days in the hopes of stopping the spread of illness and to give them a chance to disinfect each school. I don’t know about you guys, but this is the first time I’ve ever seen a school shut down because of illness. And this isn’t happening just in New Mexico, it’s happening across the country.

With all this sickness going around, parents are afraid of taking their kids into public places and some are worried about going outside. We know that being inside with a lot of people can increase our chances of getting sick, but what about playing outside?

Wive’s Tale or Wisdom?

How many of you remember your mom saying, “Bundle up or you’ll catch a cold!”

But does staying warm have anything to do with getting sick or is it just an old wive’s tale?

The Science

Let’s start with the basics. The cold and flu are viruses, not bacteria. Colds are classified as rhinoviruses and flus are classified as influenza. There are multiple strains of each virus and they tend to be highly contagious. You can pick up these viruses by touching contaminated surfaces like door knobs and toys, or directly from another person by shaking hands or walking into a sneeze cloud. These viruses can live for hours on surfaces and hands.

Because cold and flu viruses are microorganisms that you pick up from being around sick people, going outside in cold weather cannot make you sick. You must be exposed to a virus.

One reason we get sick more often during the winter months is because we spend most of our time indoors, increasing our exposure to these viruses.

Although we cannot catch one of these viruses by simply being outside, scientific studies suggest that the cold, dry weather can make us more susceptible to getting sick.

Cold Temperature and Sickness

A recent study found that cold temperatures can affect our likelihood of getting sick. In mouse models, researchers discovered that cold viruses reproduce better at colder temperatures. They learned this by looking at replication rates in the nasal cavities and the lungs of mice. Nasal cavities were 2-4°C cooler than the lungs (core body temperature) and had higher viral reproduction rates. The researchers suggested that this was due to a diminished immune response caused by lower temperatures (Foxman et al., 2015).

Dry Air and Sickness

A study found that cold temperatures and dry air can increase the spread of the flu virus in guinea pig models. The researchers looked at transmission rates of the flu by housing guinea pigs at different temperatures and humidity levels and then infecting one with the virus. They found that transmission rates increased in cold and dry climates. (And for those of you worried about the guinea pigs, they did not have flu-like symptoms.) The researchers suggested that dry conditions cause the virus to desiccate, making it lighter and stay air-born longer; therefore, infecting more people (Lowen et al., 2007). Since relative humidity is lower with colder temperatures, even the air in your home will be drier in the winter, potentially increasing the rate of viral transmission.

Mom Was Right!

Science provides evidence that there is wisdom in this wive’s tale. Although we cannot catch a cold or flu virus from simply being outside, the cold, dry air plays a role in increasing transmission rates and/or diminishing our immune system. In fact, a recent study based on 20,000 people showed that the flu season in a temperate climate was kicked off every year by a drop in temperature. Their results, however, did not show a similar effect for the cold virus (Sundell et al., 2016). There is still so much to learn regarding weather conditions, seasonality, and the transmission of diseases.

Everyday Takeaways from Science

• Simply being outside in the cold, dry winter air will not give you the flu or a cold.
• Cold temperatures can weaken your immune system making it more likely that you’ll get sick if you pick up a virus.
• Dry air helps viruses spread more easily (this applies to indoor and outdoor air).
• The science is still unclear about specific weather conditions and the spread of illnesses, but bundling up before going outside, as your mother suggested, is great advice!

Should My Kids Play Outside this Winter?

Use your best judgement and contact your pediatrician if you have any concerns or questions. I am not a medical doctor and am not providing you with medical advice.

The frequency and times in which you go outside are going to be dependent on your situation. If your child has a cold or the flu, it might be best to stay inside. Check with your pediatrician if your child has severe asthma or a diminished immune system. If your child has recently been exposed to a cold or flu virus, you might consider keeping them inside for a day or two (with a humidifier) to help their immune system combat potential illness.

If your child is healthy and feeling anxious because they’ve been cooped-up indoors for months, consider taking them outside to expend excess energy. Just be sure to dress them properly so they stay warm and dry.

How do I stay healthy?

There is no guaranteed strategy for staying healthy, but there are steps you can take to decrease your chance of getting sick. Washing your hands often, covering your mouth when you cough, and avoiding sick people are all great strategies. To get more information on ways in which you can stay healthy during the cold and flu season, visit the Center for Disease Control’s (CDC) Website. They are the leading authority on public health in the U.S. and have ample resources concerning common illnesses, vaccinations, treatments, and overall wellness.

Here is a quick cheat sheet for remaining healthy for the rest of the season and seasons to come!

• Wash your hands often.
• Get vaccinated.
• Cover your cough.
• Eat healthy foods.
• Stay hydrated.
• Get plenty of sleep.
• Stay active.
• Avoid sick people and stay home if you’re sick.
• When outside, dress in layers to stay warm and dry.

Many people have misgivings about vaccinations. And that is completely understandable, especially when it comes to your children. There is a lot of misinformation out there, and even the scientific information that we have can be hard to process at times. According to the scientific literature, vaccinations work! Check out the CDC’s infographic below to visually see the impact of vaccinations in our country. Please feel free to ask questions in the comments below. No question is stupid!

Thanks for reading,

Dr. Jenny

References:

Foxman, E.F., Storera, J.A., Fitzgeraldc, M.E., Wasike, B.R., Houf, L., Zhaof, H., Turnere, P.E., Pylec, A.M., & Iwasakia, A. (2015). Temperature-dependent innate defense against the common cold virus limits viral replication at warm temperature in mouse airway cells. PNAS. 112(3): 827-832.

Lowen, A.C., Mubareka, S., Steel, J., Palese, P. (2007). Influenza Virus Transmission Is Dependent on Relative Humidity and Temperature. PLoS Pathogens. 3(10):1470-1476.

Sundell, N., Andersson, L-M., Brittain-Long, R. Lindh, M., Weston, J. (2016). A four year seasonal survey of the relationship between outdoor climate and epidemiology of viral respiratory tract infections in a temperate climate. Journal of Clinical Virology. 84:59-63.

Disclaimer

I am not a medical doctor and am not providing you with medical advice. Any decision regarding your children should be discussed with your pediatrician and all actions regarding your children are your own.