Heating and cooling usually make up a big share of household energy use, which makes the thermostat one of the most useful tools you have. Setting the temperature a few degrees cooler in winter and a few degrees warmer in summer, especially while you're asleep or out of the house, can often reduce how hard your system has to run.

A programmable or smart thermostat makes this automatic, so you don't have to remember to change it every day. If you already have one, take a few minutes to check that the schedule still matches your routine. Many people set it up once and never revisit it, even after their work hours change.

Make changes gradually and pay attention to comfort, particularly for babies, older adults or anyone with health conditions. In very cold climates, avoid setting the heat so low that pipes could freeze. If you have a heat pump, check the manufacturer's guidance, since large setbacks may not work the same way they do with a furnace.