Many people use firewood as a source of heat during the winter months. While it may seem like a time-saving idea to stack large amounts of wood inside the home, it's best to bring in wood on an as-needed basis. When you bring in firewood, you risk introducing mold spores into your home, which can affect your indoor air quality. For people who have asthma and other respiratory illnesses, this can be a health problem. Most people want to avoid a mold infestation in their home anyway. Instead, store firewood outside in a dry place, like the front porch, and bring it in when needed.