Grandma Right? Can Cold Weather Cause Pneumonia? (Pedcast)



Topic Introduction

Now here’s a question that comes up often in the office, “Can exposure to cold air cause my children to be sick and come down with coughs, colds and even pneumonia?”  When a child gets really sick with pneumonia, parents want to know why that happened, and I can’t really blame them. I do too.  They often ask, “Is there a relationship between pneumonia and being out in the cold, getting really chilled, having wet feet, or not wearing adequate clothing like Grandma said?” You would think that in the 21st century, we would have answered this basic question, but unfortunately, we have not. The answer seems to be elusive. Well, today, it’s time for Doc Smo to weigh on the subject, not with a new study or data, but with my observations and experience -so- crank up that digital media, open up your cerebral cortex, and enjoy this installment of Portable Practical Pediatrics.

Musical Introduction

Examples of Pneumonia in Association with Cold Exposure


Let me tell you about some of the recent cases of pneumonia that I have treated where the subject of exposure to cold came up.

Case #1,

I saw a 14 year old child not too long ago who had a history of mild asthma who came to the office because of  fever and cough. Her asthma seemed to be under control and I think she was compliant with taking her medications.  The day I saw her, she had developed a high fever accompanied by a severe cough. She had been mildly coughing for about a week before her fever set in–and that fever happened to be about 4 hours after going swimming in cold water. She admitted that she gotten quite cold while swimming but she was having a lot of fun.  She denied wheezing or shortness of breath but she did have a very phlegmy cough.  Her history and examination were consistent with pneumonia that I confirmed with a  chest X-ray. Fortunately, she was able to make an uneventful recovery but her family and I did wonder whether her frigid swim had something to do with her illness pneumonia.

Case #2

This case is actually quite similar to the first except this 16 year old young man didn’t have asthma but he did have a cold when he went camping in the mountains this fall and slept on the cold ground for two nights. He does admit that he got cold at times during his slumber, especially early in the morning. The Monday after his cold sleeping weekend, he became sick with fever and an increasingly deep cough.  I’ll bet you can guess what illness he had– that’s right, pneumonia. He and his mother disagreed about whether he should have gone fall camping in the cold mountains when he was congested, but he had insisted. Certainly his mother believed that sleeping on the cold 40 degree ground had something to do with his pneumonia but even with pneumonia, the child remained skeptical.

And Finally, Case #3

My final recent case is that of a ten year old young man who loves to play touch football which he was doing this fall on a particularly cold and wet day. Just like case number 1, he too has seasonal allergy in the fall and spring and he was congested even before he went out to play with the guys. Of course, as his mother pointed out to him five times during the visit, he was not wearing his coat while playing. The boys played for hours in the cold air and of course, rolled quite a bit on the cold ground. Sure enough, within 36 hours, he too had a fever and deep cough that turned out to be on X-ray, a classic pneumonia.  What do all three of these cases, real cases, have in common you ask? Well, all have a child with a mild respiratory problem who is exposed to fairly extreme cold, be that cold water, or cold air, or the cold ground.

What Did Grandma Say?

So what is the Doc Smo theory of why this happens so often and why do so many Grandmothers believe that cold exposure makes a child sick, while the many scientists who have studied this issue and have not concluded that the cold exposure causes sickness.  Remember, to Grandma, this was an extremely important issue since in your Grandma’s era, pneumonia wasn’t just a sickness but often a fatal infection even in strong healthy young people. The word pneumonia scared her mightily.

Well, from my observations, here is why I believe there is confusion on the subject.  Exposing an otherwise healthy child to cold air or cold water or the cold ground doesn’t seem to make them sick in my experience, but,  if the child already has a viral respiratory illness of respiratory allergy or both, exposure to cold can make them very sick. So you can see, both Grandma and the researchers are right. The scientists study cold exposure in healthy children and Grandma know what happens from cold exposure to her already mildly ill children!

What is the Science Around this Subject?

Here is some evidence that backs up what I am saying,   There is strong evidence that cold, dry air promotes pneumonia and deaths- but why? Here are some of the many theories why this is the case:

-Some think dry air allows germs to travel farther in cold air since the colder air has less water.  cold climates may also allow the viruses to survive longer on surfaces and therefor be easier to spread.

-Some believe we are just indoors more in colder weather and are therefore simply more likely to touch germs

-Some believe that the cold air itself causes injury to the lungs and impairs a child’s immune response. Louis Pasteur believed and proved this was the case two centuries ago. Maybe If the child spends all their energy just staying warm, they may have  no energy left over to mount a normal immune response. That makes sense to me.

-Some believe that lack of light in the winter and low vitamin D levels is the culprit by impairing our immune response that we know requires vitamin D to function normally.

-Some believe that mood and depression are the big factors along with stress that causes a child’s immune system not to function well due to high cortisol levels that accompany stress.


So let me sum up what “I” believe after practicing pediatrics for 34 years.  A child with normal lungs don’t get pneumonia very easily, but, during cold weather, a child’s  lungs are often not normal.  As I frequently point out to my patients in the winter, children seem to be either getting sick, sick or just getting over being sick. Recent surveys show that the average child gets an amazing 6-8 respiratory illnesses/ each fall/winter/spring, each lasting about 14 days. Do the math, that means , the average child, who doesn’t have allergies, has congestion and/or cough for half the cooler days of the year. And those children with respiratory allergy or those children that attend group care with exposure to lots of other children, they have much much more of the cooler months with a congested respiratory tract than other children.


So here is my explanation of why some children get pneumonia. I think the most common “Perfect Storm” events are when an allergic child has the combination of their usual seasonal allergy along with a coexistent respiratory viral illness with or without cold air exposure.  I also see kids who just have a minor respiratory illness who also have a severe cold stress who come down with pneumonia. The cold exposure just adds extra difficulties for these children.


Remember, normal lungs don’t get pneumonia very easily but as you can see, most children’s lungs are not normal for much of the winter. And if the child happens to have inhalant allergy to boot, it’s amazing that they don’t get pneumonia more often than they do.  A strong cough, good respiratory cilia, a healthy immune system, a warm house, and plenty of food I think is what prevents the serious infection called pneumonia in most children…just like Grandma said!


i hope you enjoyed this episode of Portable Practical Pediatrics where your free pediatric education is just a touch or mouse click away. Don’t forget, you can send your comments to my blog at I would love to hear your stories and perspectives on this subject. And I have a favor to ask, if you get Portable practical Pediatrics through iTunes, take a moment an write a short review there.  And if you really don’t want to miss any of the conversation, make sure you subscribe to get notice of each new pedcast posted. And one final request, make sure you check out my parenting book, Can Doesn’t mean Should, Essential Knowledge for 21st Century Parents. Get your copy on amazon today. I’m sure you will be glad you did. This is Doc Smo, boradcasting in studio 1E, hoping that I convinced you that it’s important to insist your kids always tote, that winter heavy winter coat. Until next time.



Smo notes:

1. Debunked: 5 Myths About Pneumonia

2. Cold Stress and Respiratory infections.

3. Cold dry air promotes influenza and pneuomnia

4. Another study that found that 21 days after cold dry spell, influenza and pneumonia deaths peaks;jsessionid=5F9C50B10F6E6418EBE7905AF7B10193.f01t02?v=1&t=ijnpimso&s=904866e858785b429f8e81b15dd8dd50db4eca64

5. Open Ward versus Closed Ward treatment of pneumonia during an epidemic of 1918 Camp Wheeler

6. Chilled animals more susceptible to infections