Heating season starts now — CO calls and chimney fires climb with the cold

Cold weather is moving in across much of the country this week. The practical effect for your shift is not the temperature itself but what people do about it. Furnaces that sat idle all summer get switched on. Space heaters come out of closets. Fireplaces and wood stoves get their first fire of the year. Each of those is a predictable source of the calls that spike every autumn.

Carbon monoxide is the one to watch first. A furnace fired up after months off, a blocked flue, a cracked heat exchanger, or a generator run too close to a house all produce the same thing — an odorless gas and a caller reporting vague symptoms. Headache, nausea and dizziness across more than one person in the same building is the pattern. Treat a multi-casualty "flu" in a heated space as CO until a meter says otherwise, and carry the meter in.

Chimney and flue fires track the same curve. First fire of the season in a flue that was never swept means built-up creosote ignites. Expect them in the evening and overnight, and expect the caller to downplay it.

For dispatch, the tell is clustering: several CO or odor-of-smoke calls in one shift once the cold holds. Flag it early so the first crew is not the only one carrying meters.

Roads change too. Overnight lows near freezing put patchy ice on bridges and shaded curves before the ground frost is obvious, and wet leaves cut traction on the same bends. That feeds the MVC and extrication workload for fire, EMS and rescue, and the traffic-control load for law enforcement.

None of this is new to you. What matters is the timing: the first hard cold is the trigger, and the calls arrive within a day or two of it. Stage your CO meters, brief incoming crews, and watch the overnight board.