Ever wonder why the flu tends to strike in the colder months? Part of the reason is your furnace. Artificial heat lowers humidity, creating an environment that allows the influenza virus to thrive. (Colder outside air also pushes people together in confined indoor spaces, making it easier for the flu bug to spread). Adding some moisture to the air in your home during the winter with a warm- or cool-mist humidifier may not only help prevent the spread of flu, it may also make you feel more comfortable if you do get it.