Feel a chill? It’s not just the falling temperature. It’s the scary prospect of higher heating bills. Oil prices may have fallen, but the American Gas Association still is predicting that on average, bills for people who heat their homes with natural gas may be more than 18 percent higher this year than last. Simple things can make a difference in how much you spend this winter. We talked with Angie Hicks, founder of Angie’s List (angieslist.com), a Web site that helps consumers find contractors, for some tips.

1. Get the furnace checked. Pay to have a professional spot problems and fix them. It will be a lot cheaper than paying weekend rates for an emergency visit when the furnace cuts out on a cold Friday night. According to Hicks, 80 percent of emergency calls could be prevented with routine maintenance.

2. Change the filter. Hicks suggests you let paying the monthly gas bill be your reminder to replace the furnace filter on a forced-air system. A clean filter makes the furnace run more efficiently, using less gas, saving money and reducing air pollution.

3. Lower the thermostat. It’s an immediate way to burn less gas. If you don’t have a programmable thermostat that can be set to automatically turn the heat way down while you’re snuggled asleep or while you’re off at work, get one. Depending on your skill level and the complexity of your heating system, you may be able to install one yourself for $100 or so. A more complex professional installation might cost $200 to $300, depending on the situation.

4. Add insulation. Even if you have some insulation in your attic, you probably don’t have enough. In Chicago, Hicks recommends attic insulation with an R-value of 49 — which would require layers of standard fiberglass batting laid 19 inches deep. The batting is messy to handle, Hicks says, but easy enough for homeowners to install and inexpensive compared to the energy it saves. Other types of insulation may be more effective in tight spaces but require professional installation. Remember that many older brick houses, such as 1920s bungalows, were built with no insulation in the walls. Be sure to caulk and weatherstrip around doors and windows to seal heat-sucking small gaps.

5. Consider a new furnace. It’s an investment of several thousand dollars, but any furnace more than 10 years old is likely to burn far more gas than today’s, Hicks says. Furnaces with the Energy Star label use gas at least 15 percent more efficiently than other models (energystar.gov). It’s crucial to size a furnace just right — neither too small and unable to heat the home, nor too powerful and therefore wasteful. Prices will vary widely, depending on the size of the house and the complexity of the installation. Get bids from several contractors; question them closely about what they recommend and why; and check references, licenses and insurance before signing a contract.