This page is a room plan and a safety line. It is not a chimney-install guide, not a heater catalog, and not medical advice. Indoor combustion can kill. If a method is famous and unsafe, it does not ship here.
You are trying to keep people and pets alive through a cold night in a U.S. house or apartment. You are not trying to hold 2,000 square feet at 70°F. The fridge and the lights are a watt problem; that is how to size backup power. Heat is a room problem first.
Pick the room and close the rest
Pick one room you can close with a door. Interior is better if you have no safe heat source in it. If you already have a working fireplace or a wood stove, the room that contains that appliance is the room, because you do not invent a second fire somewhere else.
Few windows. A door that latches. Space for people, pets, and the night bedding. Towels or blankets at the bottom of doors you will not use. If the house has supply vents you can close, close the ones to empty rooms so you are not heating a hallway for no one.
Hold the heat you already have before you light anything. Layers. Hats. Shared bedding. Sun on the glass by day, curtains closed at night. Cook if you must, but a burner that heats a pot is not a room heater, and a wash-up that needs warm water is not an excuse to run an unvented flame in a sealed room. See how to wash up without running water.
Pipes are part of the plan. If a line in an unheated room will freeze, a trickle at that tap can be cheaper than a burst. That is a house-by-house call, not a rule for every apartment.
When to leave: the room will not stay livable, someone is ill, a carbon monoxide alarm sounds, or you cannot isolate a safe space. That is not a toughness test. A warmed public building is a better night than a heroic one.
Wood
A fireplace you already have will often heat the chimney more than the room. You can sit in front of it. You will not heat the house with it. Close the damper when there is no fire, or you are heating the sky.
A wood stove that is already installed can heat the room it sits in. It needs the clearances on its label, a sound flue, and dry wood. Wet wood makes smoke and creosote. Creosote is a house fire. This is not a chimney-install guide. Get the flue inspected before you lean on it for a winter. If you have never had it inspected, this week on the grid is the time, not the first night of an outage.
Dry wood is split, stacked off the ground, covered on top, open on the sides, and aged if you can wait. A stove stuffed with wet rounds smolders. A smolder is how creosote builds.
The axe that cut that wood needs a working edge and a tight handle. That is how to sharpen and maintain the three tools you actually use. This page does not teach you to install a stove, run a liner, or light a fire in a barrel in the living room.
If you do not already have a legal, inspected place to burn wood indoors, wood is not your indoor plan. Do not invent one.
Propane and catalytic
Only a heater explicitly rated for indoor use belongs indoors. "We cracked a window" does not turn an outdoor heater into an indoor one.
Even an indoor-rated catalytic or infrared propane heater burns oxygen and can produce carbon monoxide. Treat the label as the floor, not a blessing.
- Ventilation as the device requires. That usually means a window cracked, not a sealed room.
- About three feet of clearance from bedding, curtains, and furniture.
- A level surface that will not tip.
- A working battery carbon monoxide alarm in the same room. Test it on a normal day. Keep spare batteries.
- Do not sleep in a sealed room with a flame.
If the label says outdoor use only, it stays outdoors. Patio heaters, torpedo and construction heaters, and camp stoves used as furnaces are outdoor devices. Bringing them in is how people die.
A damaged or dirty catalytic pad does not work as designed. Follow the device's own maintenance, or do not use it. This page will not pick a unit for you. There is no heater recommendation here.
Unvented propane in a tight room is a common way this goes wrong. If you cannot give the device the air it asks for, do not light it. Layers and a smaller room beat a flame in a box.
What not to burn indoors
These are not style points. They are the failures that kill people in U.S. outages, and they are the line this page will not cross.
- Never burn charcoal inside a home, a garage, a vehicle, or a tent. A hibachi in the kitchen is a carbon monoxide source, not a stove.
- Never use a gas range, an oven, or a clothes dryer to heat the home. An open oven door is not "free heat."
- Never operate a portable generator indoors or in a garage, even with the door open. Opening the door does not make a garage safe. Place a generator outdoors, far from openings, exhaust away from the house. See backup power.
- Never bring outdoor-only heaters indoors: patio heaters, torpedo and construction heaters, camp stoves used as furnaces.
If the method needs you to "just be careful" in a closed room with a flame that was never rated for that room, it does not belong in the plan.
Carbon monoxide and oxygen
Carbon monoxide is colorless and odorless. You will not smell your way out of it.
It comes from incomplete combustion: charcoal, a generator, a gas oven, a heater that is the wrong device or the right device used in a sealed room. It binds to blood better than oxygen does. People go to sleep and do not wake up.
Symptoms include headache, dizziness, nausea, and weakness. That is not a night to tough out. Get out of the building and get air, then get help. This page does not treat carbon monoxide poisoning or hypothermia. If someone is injured, confused, or will not wake, that is emergency care, not a household tip.
A tight modern house can also run low on oxygen if you burn fuel and block every air path. Do not stuff towels under every gap and then light a flame. The occupied room needs the ventilation the device requires, and a working battery CO alarm in that room.
If the alarm sounds, you leave. You do not reset it and go back to bed.
How long a tank or a rick lasts
Do not treat a catalog hour-number as a measurement of your night. Output, room size, outdoor temperature, insulation, and how often you open the door all move the result. Better to under-claim.
Use a method, not a chart we invented:
- Read the device's output from its label — BTU per hour, or watts if it is electric and you already sized power.
- Know the room. A closed 150-square-foot room holds heat. A whole floor does not.
- Know the fuel on hand: pounds in a tank, or the wood you can actually reach, dry, and burn in a legal appliance.
- Divide available energy by labeled output, then cut that number. You will not get a continuous full-output night, and you should not run a flame wide open in a small room anyway.
Propane tanks list weight. The device lists BTU. That division is an estimate of hours at that setting, not a promise. A small tank on a cold night in a leaky room is a short night. Have a second plan: more layers, a smaller room, or leave.
Wood is worse to count. A rick is not a standard unit in practice; people mean different stacks. A cord is 128 cubic feet, tightly piled. What matters is how many fires you have actually run in that stove, in that weather, with that wood. If you have never burned a winter in that room, assume you have less time than you think. Wet wood shortens the useful heat and lengthens the creosote problem.
When the fuel runs out, the plan is the room you already closed, the clothes you already put on, and the decision to leave if the room will not hold. Do not "find something else to burn" that was never a heater.
A closed room and a safe heat source still leave you with wood to cut and tools that have to work. Dull steel and a loose handle are how a cold day gets worse. Next: how to sharpen and maintain the three tools you actually use.