The pros and cons of air conditioners

As the summer heats up, air conditioners will be cranking up to full blast in office buildings and homes to keep people cool. They provide welcome relief from sweltering weather and an obvious solution to prevent heat-related illnesses and deaths. But AC systems themselves can lead to health problems if not cleaned and maintained properly.

Here's what you need to know about the health pros and cons of air conditioners and how to use them safely:

Pro: Reducing heat stroke

According to the Centers for Disease Control and Prevention, "air-conditioning is the number one protective factor against heat-related illness and death," a problem that claims hundreds of lives in the U.S. each year. People who are most vulnerable to heat-related illness are children under the age of 4, adults over the age of 65, people who are overweight and those who are sick or on certain medications.

To help reduce the risk, doctors recommended drinking lots of water during the summer and staying in air conditioned areas during the hottest part of the day.

Con: Bacteria, mold and fungus

Air conditioners can be a breeding ground for the growth of bacteria and fungus. Moisture can accumulate in the coils and fan blades from condensation that forms when cold air circulates through the appliance. If left unchecked, things like mold and fungus can build up and get blown out into the air.

These microorganisms can lead to a number of breathing problems including pneumonia and Legionnaire's disease, a severe inflammation of the lungs caused by bacteria known as legionella.

Pro: Easing allergies and asthma

For people with allergies or asthma, research shows that air conditioning can help ward off attacks. According to the Mayo Clinic, air conditioning can help filter out airborne pollen from trees, grasses and weeds to keep it from circulating indoors. Air conditioners also lower indoor humidity, which decreases the growth of dust mites and mold.

Con: Sick building syndrome

Air conditioners can contribute to sick building syndrome, a variety of conditions that are brought on by time spent in certain indoor environments. Symptoms may include dizziness, dry throat, itchy eyes and nausea. A study in the journal Occupational and Environmental Medicine found that "air conditioned buildings generally have a higher prevalence of symptomatic workers than naturally ventilated buildings." One small study found that HEPA and carbon air filtration systems may help reduce symptoms and improve productivity.

Clean air advice

To ensure that your air conditioner keeps you cool and healthy this summer, make sure you regularly clean or change your air filter. Check that exhaust fans are working properly. And never store paints, cleaners, or other chemicals near your air conditioning, heating or ventilation system, as it can spread dangerous fumes throughout the house.