My opinion: I think this is especially important for people who sleep with the AC blowing into their faces. By exposing the sinuses to cold air for six to ten hours a night, I wouldn't be surprised if these people developed sicknesses. It also explains why someone like me, who usually loves the AC in hot weather, likes to sleep in a cold room with blankets on top of me - perhaps most of the drop in temperature isn't needed. Instead, it may be safer to set the AC to an optimal 70-73 degrees. That way, maybe the blood vessels will not constrict as much. For those who must frequently shift from environments of low to high temperature, though, I'm not sure if there is a solution. Is there a such thing as a mobile AC? Any other possible solutions? Feel free to comment.
Can Going In and Out of Air Conditioning Cause Colds?
How exposing the body to extreme temperature swings can lower our natural defenses
Chill DefendersAs warm-blooded animals, humans are hard-wired to keep our body temperature at around 98 degrees Fahrenheit. So when a person is exposed to frigid environments after being in the summer heat, the body "will do whatever it can to defend itself against chilling," Prof. Eccles says.
One such defense: A thermal regulator in the brain, after receiving messages from temperature sensors in the skin, automatically alerts blood vessels there to constrict. "You can see this when someone suddenly goes into a very cold building, they go pale or their skin mottles," says Prof. Eccles. The next stage is shivering, which will raise body temperature by generating heat.
At the same time, blood vessels constrict in the nose and throat, where bacteria and viruses often lurk. "If you were to look into a throat, you could see it go from a nice pink-red to a very pale color," says Prof. Eccles. "This happens within a few seconds to conserve the heat that we lose to the air we
When blood flow diminishes, the white blood cells that typically fight bacteria and viruses do too, allowing these latent risk factors to easily bloom into a full-blown cold.