Carbon monoxide (CO) poisoning is the leading cause of generator-related deaths in the U.S., and it spikes every single time there's a major storm-driven outage. It's entirely preventable with a small number of non-negotiable rules.

Why generators are so dangerous indoors

Generator engines produce carbon monoxide — a colorless, odorless gas — in far higher concentrations than a car's exhaust. In an enclosed or partially enclosed space (a garage, basement, porch, or even near an open window), CO can build up to lethal levels in minutes, often before anyone smells anything wrong, because there's nothing to smell.

The non-negotiable rules

  1. Never run a generator indoors — not in a garage with the door open, not in a basement, not in a shed. "Well ventilated" is not the same as "outdoors," and it is not safe.
  2. Keep it at least 20 feet from the house, pointed away from windows, doors and vents — CO can still drift into the house from just outside a window or door.
  3. Install carbon monoxide detectors on every level of your home, including near bedrooms — this is the backup that catches a mistake before it becomes fatal.
  4. Never use a generator in a partially enclosed space like a carport, breezeway, or tent, even briefly.
  5. Let it cool before refueling — spilled fuel on a hot engine is a fire risk on top of the CO risk.

Know the symptoms

Early CO poisoning symptoms — headache, dizziness, weakness, nausea, confusion — are easy to mistake for the flu or simple exhaustion, which is part of what makes it dangerous. If anyone in the house feels this way while a generator is running nearby, get everyone into fresh air immediately and call 911; don't wait to see if it passes.

A safer alternative for indoor backup

If your priority list is mostly indoor essentials — fridge, medical equipment, lights, Wi-Fi — a battery-based portable power station produces zero exhaust and can run safely indoors, sidestepping the CO risk entirely for that portion of your load. Use our wattage calculator to see whether a power station alone covers your needs before defaulting to a generator.