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🌡️ Sixty-Two Degrees
Everybody knows what hypothermia is. Almost everybody pictures it wrong.
They picture a mountainside, or a man who went through the ice on a pond. Something dramatic, outdoors, and well below freezing.
The National Institute on Aging says to set your thermostat to at least 68 or 70 degrees, and that even mildly cool homes — sixty to sixty-five degrees — can bring on hypothermia in older adults.
Sixty-two degrees. That is not a mountainside. That is a living room in February with the heat turned down to keep the bill honest, and a good many people reading this have sat in exactly that room and called it chilly.
There is a reason it lands harder on older people, and it is arithmetic rather than frailty. A body at seventy runs a little cooler to begin with — normal temperature drifts down about half a degree with age — so there is less road between where you start and where you are in trouble. On top of that the body's own response to cold gets blunted, by ordinary chronic conditions and by ordinary medicines that nobody thinks of as heating equipment.
And here is the cruel part. The early signs of getting too cold are confusion and sleepiness. The condition that needs you to get up and do something about it is the same condition that quietly persuades you that you are fine where you are, and would rather not.
One more thing worth saying because it is exactly backwards from what people believe: a drink does not warm you. It moves blood out to the skin so you feel warmer while you lose heat faster, and it makes you less likely to notice or act.
🔌 Your Furnace Runs on Electricity
Ask a man with a gas furnace what he will do in a long winter outage and he will very often tell you he is fine. He has gas. The gas does not go off.
The gas does not go off. The furnace does.
A modern furnace needs electricity for the ignition, for the controls, and above all for the blower — the fan that pushes the warm air through the house. No power, no fan, no heat in any room you actually sit in. The fuel is still in the line and the tank outside is still full and the house still goes cold.
The same is true of most oil furnaces, most heat pumps, most boilers with a circulating pump, and every pellet stove ever made.
So the question is not what fuel you have. It is what in your house makes heat with no electricity at all. For a good many people the honest answer is nothing, and it is far better to learn that on a mild afternoon in September than at nine o'clock on the second night.
Go and find out this week. Not by reading the manual — by asking one question about each heat source in the house: if the power is off, does this still make heat? A wood stove does. A vented gas fireplace with a standing pilot usually does. A gas fireplace with an electric ignition usually does not. Central heating of any kind almost never does. It takes ten minutes and it costs nothing, and it is the whole of the planning.
🚪 One Warm Room
We have a page on this site about the one cool room in summer, and the winter version is the same idea wearing a coat.
You are not trying to heat a house. You are trying to heat a room, and you are trying to heat it with the people in it.
Pick the room first, and pick it before you need it. The rules are plain. Small beats large. Interior beats exterior. Fewest windows wins. Below the top floor if you have a choice, because heat leaves through a cold roof faster than through anything else. And it wants to be a room you can bear to be in for four days, which rules out a good many basements and every laundry room in the country.
Then shut it up. Close the door and hang a blanket or a quilt over the doorway, because a door leaks around all four edges and a quilt does not. Roll a towel along the bottom. Draw the curtains at dusk and open them again in any sunshine you get, because glass gives heat away all night and gives some of it back in the middle of the day.
Put everybody in the same room, including the dog. Bodies are heaters — poor ones, but free, and they run all night without fuel. Sleep in there. A bed in a warm room beats a warm bed in a cold one, because the moment you get up in the night is the moment the cold gets you.
Layers on the person, not just on the bed. Long underwear, socks, slippers, and a hat indoors, which looks ridiculous and works better than almost anything else in this list.
🔥 What Actually Heats It
Now to the machinery, in rough order of how much I would trust it in a house with older people asleep in it.
A wood stove, if you already have one
Nothing else on this list makes heat for days with no fuel line, no cord and no fan. It also cooks, and boils water, and gives light, which is four jobs from one object — and our firewood page will tell you why the wood you burn wants to have been split and stacked a year ago rather than bought green in January.
The buying decision belongs at fifty, and the installing decision belongs to somebody else. A stove is chimney work, clearance work and usually a permit, and it is on this site's short list of jobs we tell you plainly not to do yourself. Have it put in properly, then have the chimney swept every year by a man who does it for a living. Creosote is what turns a stove into a house fire, and it builds quietly for a whole season without ever announcing itself.
And look at the floor when somebody quotes you. A stove needs a hearth pad under it and well out in front of the door — what comes out of a firebox when you open it does not fall straight down. A stove standing on carpet is not a stove, it is a house fire that has not got round to it yet.
Electric heat, if you have a generator
This is the one people overlook, and it fits the argument the rest of this site already makes. An electric heater puts out no carbon monoxide whatsoever. None. It is the only thing on this page you can run in a closed room and go to sleep beside.
It costs you watts, and a 1,500-watt heater is a real load — work it out on the generator calculator before you count on it. But this is the winter version of what our electric skillet page argues about cooking: run the engine outside and bring the electricity in, rather than bringing the flame in.
Follow the plain rules that come with them. Three feet of clear air on every side — beds, curtains, papers, sofas. A level surface where it cannot be knocked over. Straight into a wall outlet, never a power strip, and never a cord run under a rug.
A vented fireplace or gas heater
Vented means the combustion products go up a flue and out of the house, which is the entire point and the thing worth paying for. If it has a standing pilot it will usually work without power. If it lights electrically it will not.
Kerosene and vent-free gas
These get their own section, because the honest treatment of them takes more than a paragraph.
⚖️ The Sensor That Does Not Do What You Think
Millions of American households heat with unvented kerosene or vent-free gas, and a page that simply told them not to would be no use to the people who most need reading it. So here is the straight version.
Unvented means the exhaust goes into the room. That is not a defect. That is the design.
Everything that comes off that flame — carbon monoxide, nitrogen dioxide, carbon dioxide, and a surprising quantity of water vapour — comes out into the air you are sitting in. The damp windows people notice in a room with one of these running are not a coincidence. They are the exhaust.
These heaters are required to carry an oxygen depletion sensor, and the sensor is a real thing that does a real job: if the oxygen in the room falls to somewhere around eighteen per cent, it shuts the gas off.
Now the sentence this section exists for.
Read This Twice
The oxygen depletion sensor does not detect carbon monoxide. It measures oxygen. Those are two different gases and two different problems, and a room can fill with carbon monoxide while the oxygen level is perfectly satisfactory and the sensor sits there doing nothing, because nothing is what it is built to do about carbon monoxide. An ODS is not a substitute for a carbon monoxide alarm. It never was.
If you are going to run one, then: it needs a carbon monoxide alarm in the room with it, and a window cracked, and it does not run in a bedroom or while anybody is asleep. Kerosene wants 1-K grade fuel and nothing else — never gasoline, not once, not in an emergency. Refuel it outside, and only when it is cold. A faint kerosene smell when you come in from outdoors is normal. A strong one means stop and go out.
And check your own local code before you buy, because this is one of the places where the law genuinely differs from one place to another. California has banned unvented appliances. A good many jurisdictions forbid them in bedrooms. Some states allow them only with particular safety devices fitted. We are not going to print a fifty-state table we cannot keep current — ring your building department or your fire marshal and ask, which takes one telephone call.
🛑 The List With No Exceptions
The rest of this page has some give in it. This part has none, and it is written flat on purpose.
Never, Under Any Circumstances, For Any Length of Time
Never run a generator indoors. Not in a garage, not in a basement, not in a crawlspace, not in a shed, not on a porch and not in a carport. Outside only, at least twenty feet from the house, with the exhaust pointed away from it and the windows and vents near it shut. Opening a door or a window does not make an enclosed space safe — the Consumer Product Safety Commission says so in those words, and generators alone kill somewhere around eighty-five to a hundred Americans a year.
Never heat a room with a gas oven or a cooking range. They are not built to run for hours and they are not vented for it.
Never bring a charcoal grill indoors, or into a garage. Charcoal produces carbon monoxide the entire time it is lit, including while it is only glowing and looks nearly out.
Never use a camp stove or a propane cylinder heater made for outdoors inside a house. If the packaging does not say indoor-safe, it is not.
Never sleep in a running car for warmth, and never run one in a garage even with the door open. Snow banked around the exhaust pipe of a parked car will put the fumes back inside it.
One more, and it is winter-only so it catches people who are otherwise careful. After heavy snow, go out and clear the snow away from the outside vents of your furnace, water heater and dryer. A blocked vent sends the exhaust back into the house from an appliance that has been perfectly safe for twenty years.
🚨 The Twenty-Dollar Thing That Does the Most
Everything above is judgement. This part is a purchase, and it is the cheapest item on this site with the largest consequence.
Carbon monoxide has no colour and no smell and gives no warning at all. What it does give you is symptoms, and this is the part that kills whole households: they are the symptoms of flu. Headache. Dizziness. Tiredness. Nausea. Everybody in the house feeling poorly at once, and a family that decides there is a stomach bug going round and takes themselves off to bed.
Two things are worth knowing about that. Everybody getting ill at the same time is a signal in itself. And if everybody feels better when they go outside and worse when they come back in, that is not a bug. Get out and stay out and ring the fire department.
Buy them for every level of the house and for outside every sleeping area. Test them monthly. And check the date on the back, because the sensor in a carbon monoxide alarm wears out on a schedule whether it has ever been triggered or not — most of them are done at somewhere between five and ten years, and an expired alarm on the ceiling is worse than no alarm at all, because it is doing the job of making you feel covered.
If you heat with anything that burns — wood, gas, oil, propane, kerosene — this is not optional equipment and it is not a winter-only purchase.
💰 Why This Is a Fifty-Year-Old's Errand
Nothing on this page gets easier to arrange later.
A wood stove at fifty is a decision made on a fine afternoon with three quotes on the table and a whole summer to get the chimney done. A wood stove at seventy-two is a decision made in the second week of January by somebody who is already cold, and it will cost more and be done in more of a hurry by whoever can come.
The same goes for all of it. The quilt, the towel, the alarms, the question of which room and whether the fireplace works without power — every one of those is a twenty-minute job in September and an emergency in February. And the people who freeze in their own houses are hardly ever people who made a bad decision. They are people who made no decision, because the moment for making one arrived at the same time as everything else.
Cold is not a dramatic way to be in trouble. That is exactly what makes it dangerous. Nothing bangs. Nothing catches fire. Somebody simply gets a little confused, and a little sleepy, and decides they are fine where they are.
Before You Close This Page
Walk the house and name the room.
Which one would you all live in for four days? Smallest, most interior, fewest windows, and one you could stand. Then ask the one question about it: is there anything in this house that makes heat with the power off?
It takes ten minutes, it costs nothing, and it turns a bad night into a plan you already had. Nobody has to buy a thing tonight.
This page is general safety information about heating equipment, not medical advice and not a substitute for your local building and fire code, which differs from place to place and which your building department or fire marshal will tell you over the telephone. If you think anyone has been exposed to carbon monoxide, get them into fresh air and call 911.