Does Air Conditioning Cause the Common Cold?

Any office worker who has spent much time commuting in a hot, humid climate knows the potential problems of constantly going between cooled spaces and the sweltering outdoors.

While it is common medical knowledge that colds are actually caused by viruses, specifically one known as a rhinovirus, the effects of air conditioning can create situations in which a person’s immune system is weakened, thereby leading to a greater chance for catching a cold.

The basic science behind that idea, according to Mother Nature Network, is as follows: Humans are warm-blooded creatures who tend to prefer a sustained body temperature of around 98 degrees Fahrenheit. Our bodies will do all that they can to keep this temperature constant.

Therefore, when going into a cold building from a hotter atmosphere, our skin tells our brains that we have suddenly experienced a drop in temperature. This, in turn, causes our brains to tell our blood vessels to constrict, which should have the effect of warming our bodies back to an ideal temperature.

And this response isn’t just evident below the surface. One look at a person who has entered a frigid office after walking through the oppressive heat will reveal that person as having more of a pale complexion – the result of blood vessels constricting.

The constriction of blood vessels includes those in our throats and noses. As a result of slowed blood flow in those areas, white blood cells that fight infection are less prevalent, since it takes them more time to travel through narrower vessel openings. This makes it more difficult to resist a cold-causing virus. It is important to note, though, that the virus must already be present in our bodies in order for the shock of entering air conditioning to have any real influence on getting a cold.

And it’s also true that going from cooler environments to warmer ones has an opposite effect: Improved blood flow would maintain or possibly increase our levels of resistance to a rhinovirus.

You can read more of Mother Nature Network’s article here.