With the hot outdoor temperatures of summer and the air conditioners going full blast, it's common to hear people complain that the constantly changing temperatures have made them ill. Many people believe that repeatedly going from the hot, humid outdoors into buildings with cold, dry air makes them catch colds in the summer. But is it really the change in temperature – or the air conditioning – that's making them sick?
According to the National Institutes of Health, colds are caused by viral infections and are spread through viral secretions. In other words, people have to inhale or touch someone else's cold germs, either through direct contact or through an infected surface, in order to catch a cold. However, when people develop cold-like symptoms such as a sore throat, runny nose, watery eyes and even a persistent cough in the warmer months, they call them colds and blame them on the air conditioning.
While cold air – or going from cold environments to hot – does not cause or spread viral infections, there are some ways a poorly functioning air conditioning system can make people feel lousy.
Dry air: Air conditioners remove some of the humidity from the air, which can make sinuses and throat dry, scratchy and uncomfortable. When the system runs constantly, it can even make people feel congested and produce a cold-like post-nasal drip.
Dirt and dust in the vents: These can irritate the sinus cavities and make people sneeze more than usual.
Poor filtration: A dirty or clogged filter might fail to remove pollen, pollution or other allergens from the outside air and circulate them through the building, causing allergy symptoms such as post-nasal drip, sinus problems and watery eyes.
Leaky or malfunctioning systems: Excessive moisture can create wet areas in the air conditioning system or in the building, harboring mold or mildew and blowing the spores throughout the interior. People who are sensitive to mold can develop a runny nose or even a cough in response to the heavy spore load.
As the outside temperatures get higher and homeowners make their A/C systems work harder, more pollutants are released into the home and residents can begin to feel ill. Some people are more sensitive to dry air, which can make the symptoms worse. But unless you have actually come in contact with someone who has a cold virus, the symptoms are probably caused by the poor air quality. If you always seem to "catch a summer cold" when outdoor temperatures start to rise, have an air conditioning service examine your system for problems. A thorough cleaning and tune-up can help you enjoy the summer and go from cold rooms to the warm outdoors without the "summer cold" symptoms. Contact an HVAC contractor if you need help with your air conditioner.