The humidifier
Hooking up a humidifier can bring you much-needed relief from cold-weather ailments like stuffy nose and dry skin. The downside: if not cleaned properly or often enough, humidifiers can grow mold and pathogens, spewing plumes of the stuff into the air, says Miguel Wolbert, MD, medical director of West Texas Allergy in Midland, Texas. Plus, having too much moisture in the air can turn your home into a breeding ground for dust mites, a problem if you suffer from indoor allergies.
Stay safe: After running the humidifier at night, don't just turn it off and let it sit. Freestanding water left in the bowl is what will accumulate mold. Empty and dry it out completely. The Environmental Protection Agency also recommends cleaning portable humidifiers every third day by using a brush or scrubber on the tank to remove deposits and film.