Top MDs: Your Air Conditioning Can Make You Sick. Easy Ways to Feel Better Fast

Every summer, when the heat gets unbearable, those of us who are fortunate enough to have air conditioning end up turning it up to beat the sweltering summer heat. And the relief we feel when we do is very real! But it turns out there's a hidden downside to this: By harboring mold, allergens and even bacteria and then recirculating those things into your environment, your air conditioning can make you sick. Read on to discover what you should be cleaning, checking and replacing on your unit to stay cool — and healthy! — as well as how to ease any symptoms you may currently have.

That cool air you rely on in the car, at work or home is produced by your air conditioner pulling warm, sometimes humid, air from the room, explains air conditioning expert Dave Roebel, owner of Northeast Mechanical Services. Then the machine cools the air via a liquid refrigerant. Fans pump that cooled, less-humid air out of the unit into the room (or car) to maintain your desired temperature.

But that cool air can cause problems for some people. Indeed, a study in the International Journal of Epidemiology found a link between air conditioning exposure and sickness. Here, doctors explain some symptoms you can experience and remedies to help you feel better.

Mold can thrive in air conditioning units due to the moisture they generate, says Michael Golubev, CEO of Mold Busters. “Mold growth is especially common in humid climates or during rainy seasons.” (Click through to see how mold exposure can impact your energy levels.)

If your air conditioner has become a breeding ground for mold, inhaling those microscopic mold spores kicks your immune system into overdrive to fight off the fungi, which creates congestion-causing inflammation, explains Michelle Thompson, MD, a functional medicine physician and founder of Epoche Medical in Coral Springs, Florida. The good news: Short-term exposure to small amounts of mold won’t cause any long-term side effects, and your symptoms should ease within two to three days of getting rid of the mold. (Scroll down to find out how to rid your unit of mold by changing your filter.)

Feel-better fast: In the meantime, consider placing an English ivy plant in rooms that you spend the most time in. The plant can eliminate 78% of airborne mold, according to a study presented at a meeting of the American College of Allergy, Asthma and Immunology.

Also smart: If your thermostat’s reading indicates the indoor humidity level is lower than 40% to 50%, David Corry, MD, a professor of Immunology, Allergy and Rheumatology at Baylor College of Medicine, recommends raising your air conditioner’s temperature a degree or two, which will quickly ease congestion. “You can also try a room humidifier to hit the sweet spot of having enough moisture to prevent your air conditioner making you sick without your room or house feeling too damp and tropical,” he says. This is especially helpful in your bedroom to reduce the odds a stuffy nose will keep you up all night.

Redness, itching, tired eyes and feeling like you have a piece of fuzz or a grain of sand stuck in your eye are all symptoms of dry eye, a condition that occurs when your eyes can’t produce enough tears to keep your eyes properly moist. Women are more susceptible than men to dry eye, and spending a lot of time in air conditioning can raise the risk, says Rahul Pandit, MD, an ophthalmologist at Houston Methodist Hospital.

Feel better fast: If your air conditioning is wreaking havoc on your eyes, first be sure to adjust the vents on your unit so it’s not blowing air directly in your face. Then, to soothe dry, itchy eyes, place a cold, damp washcloth over your eyes — a strategy that worked as well as eye drops to soothe dry eye in one study. Drinking a cup of coffee can also help. Researchers reporting in the journal Ophthalmology found that the caffeine in coffee increased tear production, and participants often noticed results within 45 minutes. (Click through to learn how screen time can lead to dry eye — and how to avoid it).

Even though the air passes through a filter designed to trap pet dander, dust, pollen and more, these microscopic allergens and particles can still sneak out, getting blown back into the room along with the cooled air. As these tiny irritants circulate, they can lead to a host of bothersome symptoms. Sara Chen Xie, MD, an otolaryngologist at Houston Methodist Baytown Hospital, notes that even a small amount of dust can have you battling uncomfortable sinus symptoms like pain or pressure, headaches, a sore throat or cough. What’s more, says Dr. Corry, “Pre-existing allergies are often worsened if there’s even trace amounts of mold or there are other allergens in the air conditioning unit.”

Feel better fast: To eliminate dust, when you leave the house and your a/c is off, open two windows on different sides of the room so you get a cross-breeze. UCLA researchers say this strategy flushes out dust and other airborne pollutants. (Click through to learn how a kitchen staple can eliminate dust.)

For immediate relief from congestion, Dr. Xie suggests using a saline nasal rinse to clear dust, pollen and other irritants from your nose. Research in the International Forum of Allergy & Rhinology shows that flushing out nasal cavities with a Dead Sea salts rinse reduces sinus problems like congestion, pressure and pain. That’s because the salts contain anti-inflammatory minerals like calcium, magnesium and potassium. “It helps to thin mucus, flush out irritants and cleanse nasal passages,” explains natural health expert Josh Axe, DNM.

To get the benefits: Boil 1 cup of tap water (or use 1 cup of distilled water), then add 1⁄2 tsp. of Dead Sea salts and let cool until lukewarm. Pour the solution into a neti pot and use as directed to flush your sinuses. Dr. Axe recommends repeating daily whenever you need relief.

There’s no need to break up with your air conditioner or live with your symptoms. Instead, try these handy tricks to keep cool — and healthy — all summer long.

Studies show that air conditioning filters are teeming with sick-making bacteria. That’s why it’s so important to keep in clean. Roebel's advice: “Turn off your air conditioner and clean — or, even better, replace — the filter and clean cooling fins, the exterior of the unit and the condensate drain pan and line to prevent mold growth and reduce allergens from being blown into the air." (Click through for detailed instructions on how to clean your air conditioner's filter.)

Replacing your old filter with a HEPA (High Efficiency Particulate Air) filter will further reduce circulating allergens, notes Dr. Xie. Wearing a mask while swapping out the filter can help limit your exposure to any mold spores, says Dr. Thompson.

As a general rule of thumb, experts advise inspecting your air conditioner’s filter every month and replacing it every one to three months. If you still experience symptoms after a month or notice the mold regrowing, you may need to purchase a new air conditioner.

Switch on your unit’s fan feature to continuously cycle air — even if it’s not being cooled — in your home to prevent humid, stale air from creating the perfect environment for mold to grow, advises Roebel. He also suggests using the humidity control feature on your air conditioner, if it’s equipped with one, to further control humidity in the air and discourage mold growth.

No A/C in your house? Check out these stay-cool secrets:

10 Easy Ways to Stay Cool This Summer Without an Air Conditioner

Why You Can’t Sleep When It’s Hot Out — And, How to Stay Cool at Night

3 Easy Keep-Cool and Look Great Summer Hairstyles

A version of this article originally appeared in our print magazine, First For Women.