While you stay bundled up indoors what happens outdoors can negatively affect the health of your house.  Before the winter cold sets in, check off these items. Familiarize yourself and responsible family members with gas main valve, water main valve and other appliance valves to assure that when needed, everyone in the household knows where to look quickly to avoid panic.  Check HVAC filters, and operation before heating is needed to assure everything is working properly. It