Prevention of Carbon Monoxide Poisoning

The power has been out four hours and the house is down to fifty-eight degrees. The generator is in the garage. Advice on how to prevent carbon monoxide poisoning will tell you not to start it there, and that advice is right. What it will not tell you is what the alternatives are worth in hours. The prohibition list on this subject is short, it comes from CDC and the US Fire Administration, and it has not moved in years, so this page carries it once, in one table, and spends the rest of its words on the part the list stops at: what you can run for heat, for how long, and at what point the answer becomes leaving.

In 60 Seconds

• The prohibition list is the same wherever you read it and it is correct: no generator, grill, hibachi or camp stove indoors or in a garage, and no range or oven for heat. The table below carries it once.
• A plug-in electric heater draws up to 1,500 watts. A one-kilowatt-hour power station runs it for about 43 minutes.
• Nothing you can charge in advance and carry will heat a house overnight. Consumer battery storage runs phones and lights, and that is the whole of what it does.
• Two arrangements make heat overnight without putting exhaust in the room, and a household buys both in October rather than during the storm.
• Alarms on every level and outside sleeping areas. Of the 51 US jurisdictions in our records, 37 name a fuel-burning appliance as the feature that turns that into a legal duty.

The Whole Prohibition List, Once

CDC, the US Fire Administration, four hospital systems and a state health department publish this material in near-identical form, because they are restating the same federal guidance. Repeating it at length adds nothing, so here it is compressed, with the page that carries the detail named in the third column.

One item on that list gets printed as an alarm response and should not be: opening a window. Ventilation moves the number down while the source keeps running, so it buys minutes and hides the reason you needed them. Leave, then find the source.

What 1,500 Watts Costs in Stored Power

An electric heater is the one heat source with no combustion and therefore no CO, which is why prevention lists point at it, and it is the one heat source an outage takes away. Lasko rates its ceramic tower models at 900 to 1,500 watts, 7.5 to 12.5 amps at 120 volts, and 1,500 is the top setting on the 120-volt plug-in heaters sold here. An hour of that costs one and a half kilowatt-hours, and measured against anything you can store, that is a large number.

The capacities are the manufacturers' own: Jackery's current line runs from 640 Wh to 2,042 Wh, and Tesla's datasheet gives Powerwall 3 as 13.5 kWh usable out of 14 kWh total. Every runtime in the third column is our division and nothing more, and real figures land below it once inverter losses are counted.

The car battery deserves its own paragraph, because it is the improvisation people reach for. Reserve capacity is the published figure: the minutes a fully charged 12-volt battery delivers 25 amps before it falls to 10.5 volts, and a group 35 case, a common passenger-car size, is built to 80 to 120 of them. A hundred minutes at 25 amps is about 500 watt-hours. A 1,500-watt heater asks the same battery for roughly 125 amps, five times the rate that figure was measured at, and lead-acid surrenders less total energy the harder it is pulled. Under twenty minutes is the ceiling rather than the estimate, and the battery finishes at the voltage the test stops at, which will not turn a starter motor in the cold.

Stored power protects a phone, a router and the contents of a fridge. It will not carry a room through a January night, and a household that built its plan around the assumption that it would is the household that starts something in the garage at four in the morning.

Two Arrangements That Heat a House With the Grid Down

Both keep combustion out of the air you are breathing, and both are bought and installed before the weather, which is the reason they belong on a prevention page rather than an emergency one.

A generator outdoors, feeding the house through a transfer switch. Combustion stays 20 feet away and the heat arrives as electricity, which is the cleanest resolution of the whole problem. The improvised version is a cord run out of a window, and it fails on a rule most people have never read: CPSC's own guidance on portable electric heaters says never to power the heater with an extension cord or a power strip. A transfer switch is an electrician's job with a permit attached, so this route is a decision you make in autumn. Generator placement covers the distance and the switch.

A sealed-combustion appliance that makes its own control power. A direct-vent wall furnace pulls combustion air from outside through one tube and pushes the products back out through the other, so the room air is never part of the fire. Williams describes the design in those terms. The gravity models take it further and need no house current at all: Empire's manual for the DV-210 and DV-215, rated at 10,000 and 15,000 BTU per hour, says the heaters are designed for self-generating circuits, and the pilot is lit by hand and held in by a thermopile that the flame itself powers. Nothing in that sequence touches a wall socket, which is why the appliance is still running when the street is dark.

Check the spec sheet rather than the category, because the same product family includes fan-assisted models that stop when the power does. And a vented appliance is not the same thing as a vent-free one: the vent-free category burns in the room by design and carries its own argument, which sits on space heaters and CO.

Everything else that burns belongs outdoors. Two arrangements is the whole list, and the shortness of the list is the finding.

Deciding Before the House Gets Cold

FEMA answers the question directly and then stops. Its power outage page says to go to a community location with power if heat or cold is extreme, and to check with local officials about heating locations open nearby. The Red Cross says the same thing in its own words. Neither tells you when the sentence is about you, which leaves a household to work out at two in the morning what it could have settled in daylight. Four things settle it, and none of them is a thermometer reading on a person.

• The utility's restoration estimate, not the forecast. Utilities publish one and revise it. If the estimate runs past the runtime you calculated above, the decision has already been made for you and the only question left is whether you leave while the roads are open.
• Whether you own either arrangement in the previous section. If not, the house has no heat, it has stored heat, and stored heat is a quantity that only goes down.
• The plumbing. The Red Cross puts 55 degrees Fahrenheit as the floor for an unoccupied house, because that is where frozen and burst pipes start to be the bigger loss. Pipes run on the building's clock, not the household's, and they keep running after everyone has gone to bed in coats. And if they do freeze, the thawing is its own carbon monoxide scenario: the same Red Cross page says to use an electric heating pad, a hair dryer, a portable space heater kept clear of anything flammable, or towels soaked in hot water, and "Do not use a blowtorch, kerosene or propane heater, charcoal stove, or other open flame device." Every item on that second list burns fuel in a crawlspace or under a sink, which is a small volume with a person in it.
• Whether anyone in the house is at risk from the cold itself. That is a medical question and this page does not answer it. Take it to CDC's extreme cold guidance or to a clinician, and treat the answer as the one that outranks the other three.

If the power is on tonight, find out where your county opens its warming centres and write the address somewhere that works without a charged phone. FEMA's instruction to check with local officials assumes you still have a way to check.

Which Feature of Your House Attaches a Legal Duty

No institutional result on this query mentions law at all, and prevention is where the statutory layer is at its most useful, because the question stops being "what does my state require" and becomes "which part of this building is the part that triggers it". Our records hold five typed trigger fields for all 51 US jurisdictions, and they split into two features a building has and three events a household schedules.

The features come first because they decide whether you are inside the rule at all. 37 of the 51 jurisdictions name a fuel-burning appliance as a trigger, 3 record that it is not one on its own, and 11 have not been established either way. 31 name an attached garage, 3 record that it is not a trigger, and 17 are unread. Neither of those is something a household changes.

The events are the useful half, because a household picks their dates. 32 attach the duty to new construction, 19 to work that needs a building permit, and 11 to a sale or transfer, with 30 and 34 respectively still unestablished in our reading. A furnace replacement or a kitchen job that pulls a permit is the cheapest moment a house ever has to come into compliance, because the inspector is coming anyway. Waiting for the sale is the most expensive, and in 11 jurisdictions it is also the moment somebody else's lawyer starts asking.

Those unresolved counts are records nobody has read yet, and treating them as negatives would publish research that has not been done. Your own state page is the authority on which trigger your jurisdiction uses. If the appliance belongs to a landlord rather than to you, the duty and the tenant's remedy when it goes unserviced are recorded per state on the rental requirements hub.

Sources & References

• US CPSC, Carbon Monoxide Information Center
• US CPSC, Reducing Fire Hazards for Portable Electric Heaters
• US CPSC, Generators and Engine-Driven Tools
• CDC, Carbon Monoxide Poisoning
• FEMA Ready.gov, Power Outages
• American Red Cross, Preventing and Thawing Frozen Pipes
• NFPA, Carbon Monoxide Safety
• Empire, DV-210 and DV-215 direct-vent wall furnace manual

Last updated: August 7, 2026