Evaluate your current heating system. Like so much else in your home, your HVAC system requires regular maintenance in order to perform at its peak. For that reason, it’s only prudent to have the furnace inspected every year, ideally before winter even begins. If yours is a forced-air system, consider hiring a specialist to assess the ductwork as well. Notoriously prone to heat loss, ducts are often leaky enough to compromise energy efficiency by as much as 50 percent. That may be one reason why, even when your thermostat is set to a toasty temperature, you're still uncomfortable.