Cold Air and Colds

My son is four months old. The baby sitter takes the kids outside. It’s rather cold and windy here in Japan. Is it dangerous to my son’s lungs or respiratory system to inhale cold air?

Cold Air and Colds

Dr. Greene`s Answer:

For generations, parental wisdom has held that cold air is not good for children’s respiratory systems. In particular, cold air has been thought to cause colds (thus the name). Earlier medical traditions have tended to agree with folk wisdom. Over the last fifteen years or so, the prevailing medical opinion has shifted to a different point of view. The more recent thinking is that cold air does not cause colds, bronchitis, pneumonia, or other respiratory infections. Scientifically designed experiments have been carried out to prove the theory that cold temperatures do not cause the common cold.

Studies conducted at the University of Virginia made the news when healthy adult volunteers cavorted in the snow with few clothes on and were found no more likely to catch respiratory infections than their companions indoors. Subsequently, at McMurdo Station, a US research base in Antarctica, several important studies have been carried out. (What better place to study the effect of cold temperature than Antarctica?) People in isolation at this base tended to get no colds at all — unless visitors came from the outside. Specific viruses that the visitors brought to the station worked their way through the research compound at a rather leisurely pace, approximating the rate of cold acquisition in other climates. This demonstrated that cold temperature itself does not cause colds.

The scientific studies are rather convincing, but let’s consider other known impacts of cold air on the respiratory system. First, cold air affects an important defense mechanism — mucus transport. The entire respiratory system is coated with a very thin layer of mucus called the mucus blanket, which rests on tiny hairs called cilia. This mucus blanket traps particles and organisms before they can reach the lungs. This constantly moving blanket acts as a conveyer belt to move the particles out of the respiratory system. Proper action of the mucociliary blanket depends on the mucus having the appropriate mixture of stickiness (to catch the particles) and fluidity (to move the particles up and out). When this is altered by dry air, irritating chemicals, cigarette smoke, or any other factor, the respiratory system becomes more susceptible to infection. Cold air stimulates an increase in mucus production, but like other substances, mucus becomes thicker in colder temperatures. Thus, inhaled particles are cleared less easily when a person breathes cold air.

The second area where cold air impacts respiratory health is in the nose. The nose is a remarkable organ designed to condition inhaled air in order to protect the delicate lung tissues. Whether the inhaled air has a relative humidity of one percent or ninety percent, the nose adds or extracts moisture so that air reaching the lungs has a constant relative humidity of about 75%. The same is true of temperature. When breathing through the nose, one may breathe in air at 40 degrees Fahrenheit or at 100 degrees Fahrenheit, but within a quarter of a second the air temperature is quickly brought to 98.6 degrees. Many tiny blood vessels are used to affect a temperature exchange. When a person breathes cold air, the tissues lining the nose swell as the capillaries dilate, bringing warm blood to heat the cool air. Excess blood in the nose is the cause of nasal congestion (nasal congestion is backed up blood, not increased mucus). In addition to the congestion, the mucus normally present in the nose becomes increased and thicker. Cold air, by itself, can produce nasal congestion and stuffiness, which again make it more difficult for the body to remove inhaled viruses and bacteria.

The third area of impact is in the lungs themselves. If cold air reaches the lungs, the lungs respond by releasing histamine. In people with sensitive airways or asthma, this causes wheezing. In fact, many theorists believe exercise-induced asthma is actually triggered by room-temperature air reaching the lungs in large quantity due to mouth breathing, rather than directly from exercise itself.

Piecing the available evidence together, I draw a different conclusion than either traditional wisdom or current medical opinion — 1) It is clear that in order to catch a respiratory infection of any type, one must be exposed to the causative organism; 2) If exposed, however, it is more likely that an individual will become sick if he or she has been breathing cold air.

With this in mind, here are some ways to minimize the risk of getting a cold:

  • For those who must be outside in the cold, breathe through the nose to prevent the cool air from getting to the lungs.
  • Drink large amounts of fluids — this can noticeably thin the mucus and make the mucociliary clearance more effective.
  • Wash one’s hands frequently, which will reduce the number of organisms available to enter the mouth and nose.
  • If appropriate, decrease contact with sick children and adults to decrease exposure to respiratory organisms.

As is often the case, when parents and scientists tend to disagree, both sides have important parts of the truth. In synthesizing the two views, a more accurate view emerges.

Dr. Alan Greene

Dr. Greene is the founder of (cited by the AMA as “the pioneer physician Web site”), a practicing pediatrician, father of four, & author of Raising Baby Green & Feeding Baby Green. He appears frequently in the media including such venues as the The New York Times, the TODAY Show, Good Morning America, & the Dr. Oz Show.

  1. Lisa saber

    My son is 11 yrs old and every time we have cold spells in south Florida he starts coughing throughout the whole day. He does not have asthma, nor the common cold, just violent dry coughing without phlegm production. I know the culprit is sudden cool air, but why? I am getting winded from hitting every brick wall to uncover this mystery. Can you please clue me in? I’m desperate and your wealth of knowledge will vastly be appreciated.

  2. Jean

    I have a 79 year old mother and she was diagnosed with or rather started to show signs of pneumonia(from the results of her X-ray) but the doctors and nurses( she was in the hospital due to vagovasal attack)treated her pneumonia by giving antibiotic through IV…and I have not follow up with her doctor yet due to cold weather,she was out from the hospital a week concern is,is it okay to give her a shower or giving her a bath during the day coz my sister was so worried that her pneumonia might go back? And she won’t let me bring her outside coz of the weather (cold air)

  3. Can Stress & COOL Air can affect Person with HYPERTHERMIA :: Pls Suggest :: As my Brother is Suffering with these Problem

  4. Christine

    Thank you so much for this info. I know from experience that when I have a chest infection, I do much better if I stay warm and breathe in warm air. I have just come from a hospital where the nurses told me that I was wrong and that it doesn’t matter if my Dad, who has pneumonia, breathes in cold air.

  5. Hi GTD,

    Great question!

    We’ve just added a new feature — Ask Dr. Greene! If you have a question, just go to and submit your question.

    Dr. Greene would love to answer every question that is asked, but he can’t (so many great questions). He can answer one question a day and he’s decided to let our readers decide which question they would most like to see answered.

    Here’s how it works – Once a day Dr. Greene will answer the question with the most votes from readers. That means, you have a better chance of getting your question answered if you invite your friends to vote.

    Check it out — — and let us know what you think.

  6. I spent an hour or two outside shoveling heavy wet snow. Ended up with a horrid cough less than an hour later. Now I have a slight fever and am achy. This happened before. I never knew breathing in cold air could cause this.

    • Wes

      I agree with DR Green. I’m not a doctor. I’m 52 years old. I speak from personal experience and much reading on the subject. My opinion is that cold air does not cause you to be sick unless you already have some type of lung problem. If you have a lung infection weather you know it or not then breathing cold air can make it much worse weather it’s inside or outside air. Moving air also makes it worse like being outside or using a fan inside. I suspect you already had the infection then getting out in the cold made it much worse.

      Recently I had a bronchial virus that got better and worse twice over a three week period. I got the virus from my daughter when she started her first two days of preschool. I felt I was almost completely over it. I took the kids out in the cold night air to play with a Christmas gift. We ran around and played for 30 minutes or so. The next morning I woke and was very congested again, coughing and the low grade fever was back. No one else was sick. I felt 70% better the next day but the recurrence has caused the lung infection to linger. This has been my consistent experience over the years.

      I have found that breathing cold air makes lung infections worse and breathing warm moist air makes an improvement. Moving cool air is the worst. Taking a hot shower helps. I block the cracks in the door and turn my bathroom into a steam-room. I shower and stay in their for awhile. It breaks up the mucus and helps me to cough it up. Also do not use cough syrup unless it contains an expectorant. Suppressing the cough just keeps the mucus and infection in your lungs. Drinking a lot of water helps. Stay away from things like coffee and antihistamines that might dehydrate you. Rest, warm air, steam and lots of water will help a lot with congestion.


Leave a comment

Your email address will not be published. Required fields are marked *