The Invisible Threat: What every home should know about carbon monoxide this winter

As furnaces fire up and windows close tight, a silent, odorless gas becomes one of the most dangerous hazards of the season.

You can't see it. You can't smell it. You can't taste it. But every winter, carbon monoxide quietly sends Hoosiers to emergency rooms — and in the worst cases, claims lives.

Often called the "silent killer," carbon monoxide is a gas produced whenever fuel burns incompletely. That includes the natural gas, propane, oil, wood, and gasoline that power furnaces, water heaters, fireplaces, and vehicles. When that equipment isn't properly maintained or ventilated — or when someone makes a dangerous choice, like firing up a grill or generator indoors — CO can build up to lethal levels without anyone noticing until it's too late.

The good news: carbon monoxide is almost entirely preventable. The fix starts with a few small habits and the right equipment in the right places.

Put a detector on every level of your home, and outside every bedroom. Test them regularly, and don't wait for a chirp to replace batteries. Have a professional inspect fuel-burning appliances annually. Keep chimneys and vents clear. Never use a stove or oven for heat. Keep charcoal and generators outside — always. Even a garage with the door open isn't safe enough for a generator. Open the garage door before starting your car.

Carbon monoxide poisoning doesn't announce itself. The early symptoms mimic everyday illness: headaches, dizziness, nausea, vomiting, and irregular breathing. The danger is that someone feeling flu-like symptoms at home may simply go lie down — exactly the wrong move.

If a CO detector sounds, or if anyone in the household experiences these symptoms, the response is simple: get out immediately. Leave the door open behind you on the way out, head to fresh air, and call 911. Do not go back inside until emergency responders have tested the air and confirmed it's safe.

Carbon monoxide doesn't give second chances, but it does give warnings — if you've installed the right detectors and know what to listen for. This winter, the best defense against an invisible threat is a visible plan.