Space heaters

Space heaters, ranges, ovens, stoves, furnaces, fireplaces, and water heaters "release gases and particulates into the air,” Calhoun adds. “There is also the fairly intense burden of allergens with indoor air quality such as pets, house dust mites. And perennial (year-long) allergens are 10- to 100-fold higher indoors than out.”

Bad air can trigger coughing, chest tightness, sore throat, watery or itchy eyes, shortness of breath, and even a full-blown asthma attack. “If you live in a home with chronically poor air quality, you can experience frequent headaches, long lasting colds, and bronchitis as well as chronic asthma,” says E. Neil Schachter, MD, the medical director of respiratory care at Mount Sinai Medical Center in New York.