Scientifically designed experiments have been established to prove the theory that cold temperatures do not cause the common cold.
For generations, wisdom has held that cold air is not good for respiratory systems. In particular, cold air has been thought to cause colds. Earlier medical traditions have tended to agree with folk wisdom. Over the last fifteen years, 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.
Studies conducted at the University of Virginia made the news when healthy adult volunteers played in the snow with little 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, a few 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, approximating the rate of cold acquisition in other climates. This confirmed that cold temperature itself does not cause colds.
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 organisms and particles before they can reach the lungs. This 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 suitable 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 is where cold air impact respiratory health is in the nose. The nose is an extraordinary 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 steady 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 in cold air, the tissues lining the nose swell as the capillaries dilate, bringing in warm blood to heat the cool air. Excess blood in the nose is the cause of nasal congestion (nasal congestion is backed up blood). In addition to the congestion, the mucus normally present in the nose increases and gets thicker. Cold air, by itself, can produce nasal congestion and stuffiness, which again make it more difficult for the body to remove inhaled bacteria and viruses.
The third area of impact is in the lungs. If cold air reaches the lungs, the lungs respond by releasing histamine. This causes wheezing in people with sensitive airways or asthma. In fact, many theorists think 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.
Here are some ways to minimize your risk of getting a cold.
- For those who must be outside in the cold, breathe through the nose to stop the cool air from getting to the lungs.
- Drink a lot of fluids — this can noticeably thin the mucus and make the mucociliary clearance more effective.
- Wash 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 lower exposure to respiratory organisms.
Author: Blaine Pollock
Philanthropist and Businessman, Blaine Pollock is the creative force behind World News MD/Depression.net. Blaine is also the author of the newly released Children’s Book “O My Walter”. Find the magical book, “O My Walter” at www.omywalter.com