The safest ways to stay warm during a power outage

Beware carbon monoxide.
A stone building under power lines during a snowstorm.
When the power's out and it's cold outside, you need to find a way to keep warm. michael podger/Unsplash

It’s cold—below freezing, maybe. You just lost power. Heat too, perhaps. Now you’re trying to figure out the best way to stay warm without electricity. We’ve got you.

What not to do

When the temperature indoors drops, it can be tempting to seek out quick fixes in an effort to keep you and your family comfortable or—if the situation is dire—from freezing to death. You may consider turning on alternative heat sources that don’t rely on freshly squeezed grid juice, like an oven, a car, a generator, or indoor heaters that don’t require electricity. Unfortunately, they can also be deadly.

The culprit here is carbon monoxide, which the Centers for Disease Control and Prevention bluntly describes as “an odorless, colorless gas that can kill you.” This silent killer shows up any time you burn fuel, and it can quickly take over a home. Symptoms of carbon monoxide poisoning may resemble the flu (vomiting, dizziness, and all that), and drunk or sleeping people can die from it before they even notice they’re sick, the CDC says. If you start to feel sick, or if your carbon monoxide detector goes off (you should really have one), get out and get some fresh air, no matter how cold it is.

That’s not to say generators are forbidden, but only battery-powered ones should join you indoors (and you should always follow the relevant instructions and safety recommendations). If you have one burning fossil fuel outside of your house, keep it away from any open windows or doors while pointing its exhaust away from the building, says Jonathan Otis, deputy fire chief in the often frigid city of Duluth, Minnesota.

If you’re truly desperate and need to hop into your car or truck for immediate warmth, don’t do so indoors, even if the garage door is open, the CDC says. Carbon monoxide poisoning is much less likely to happen if you’re parked in your driveway or on the street, but you must make sure your tailpipe isn’t blocked by snow. There’s also always a chance that your exhaust system is leaking into your vehicle’s passenger compartment, so pay attention to how you feel.

Dress in layers

It’s much easier to heat a small space than a large one, and the smallest area you can comfortably occupy is your own body. Focus on that first. Layers matter because body temperature regulation is critical to staying warm when the air around you is anything but. Your main goal is to keep your natural heat close to your body as long as possible.

The more clothing you wear, the easier it will be to remove and add pieces so you’re neither shivering nor sweating. Sweat means wet clothes, and that can be deadly when it’s cold. Because water conducts heat so well, perspiration is an involuntary act of self-sabotage when you’re fighting off the winter chill—it will sap you of your precious heat and render your clothes ineffective at the same time.

Ideally, you’d have well-insulated clothes to choose from, but most people aren’t prepared for the frozen wilds and you’ll probably have to make do with what you have. Your best bet will be synthetic fabrics, as they wick moisture away well and dry faster. Try to avoid natural fibers like cotton or hemp because they absolutely soak up sweat. Beyond that, just put on as many layers as you can until you’re cozy, even if you have to wear other people’s clothes. Don’t neglect your hands, feet, and head. Those masks or other face coverings you’ve been wearing during the COVID-19 pandemic can come in handy too—they will trap heat from your breath against your face, but you should change them as they get wet from condensation.

[Related: Mask up without breaking out. Here’s how to prevent pandemic acne.]

If you don’t have enough clothes, outdoor survival tips can help. In the wilderness, stuffing your clothes with insulating material such as leaves and grass can bulk up the airspace within your garments, keeping you nice and warm. In your home, you can use crumpled paper or packing material.

Pick a spot and close it off from the rest of your home

Once you’re dressed, it’s time to relegate everyone in your home (plants and animals too) to as few rooms as possible. We’ll say it again: Smaller spaces are easier to heat up than large ones, so try to stick to one room if you can. In milder situations, you may not have to go this far, but if you’re looking at a sustained lack of heat and brutal temperatures, it’s time to start hunkering down.

You likely know the warmest room in your home, but if you’re not sure, try to choose an upstairs room that has little contact with the outside air (even exterior walls). The reasons are simple: heat rises, upper ceilings can be better-insulated than middle floors, and you’re less likely to lose warmth to drafts and the winter air the farther you are from it. Of course, sitting in a dim or dark interior room can be depressing, so consider that, too.

A setup close to or including a bathroom or the kitchen would work well, but the latter is less essential considering you can store food in your chosen room and the appliances may be useless in a power outage anyway.

Next, isolate your new living space from the rest of your home and insulate it well. Shove towels or unused articles of clothing under doors and windows to block drafts, and hang blankets or sheets over doorways (especially if they don’t have doors). Pro tip: The wood that forms the sides of an entryway often continues straight up to the ceiling, so you should have no problem nailing cloth to the wall. Tape will work too, but it could strip off your paint.

If it’s sunny, open the blinds over any windows to let our friendly neighborhood star heat your living space. Otherwise, close them for added insulation. Cover any air conditioning units you can’t take out, and if your home is poorly insulated, consider blocking the windows with blankets. Ultimately, your goal isn’t to keep all outside air from entering your home—just to insulate it well enough that heat has a hard time leaving.

Look at your floor. If it’s carpet, you’re ahead of the game. If it’s tile, wood, or another hard material, it will suck heat out of your room, so you should insulate it too. Scatter clothing or blankets around, throw down a mattress or two, and try to avoid touching it and other cold surfaces. If you have a tent, set it up in the center of the room—it’s an even smaller space that’ll be easier to keep warm than the one you’re in.

[Related: How to stay warm while sleeping in the frigid outdoors]

If you have a battery-powered space heater or one that runs off a generator, you can use it if absolutely necessary, but keep it away from any flammable material—that includes clothes and blankets. Again, make sure you understand how to use it and pay attention to any safety precautions. If you have a fireplace, ensure that it’s been properly maintained and that the flue is open for smoke to escape out the chimney. You don’t want to start a fire or unwittingly fill your home with carbon monoxide. Finally, even in desperation, don’t power an electric stove for heat either—they’re a fire hazard and you could easily forget you have a hot surface lurking in the dark. Plus, they’re inefficient and not designed to heat a room, Otis says.

Living in your powerless home

Now it’s time to think about what life will look like in your survival space. Laptops (if you have a power source like a generator or battery bank) can be an additional source of heat, and we know you don’t need an excuse to snuggle with your pets for warmth. When it’s time to sleep, get in the tent or have everyone gather in one bed to share body heat—it works outdoors and it will work in your home. Just make sure to remove some layers if you get too hot—it’ll prevent you from sweating.

When you’re awake, give your body the energy it needs to create heat by eating and drinking regularly. Warm food and drink is ideal, and room-temperature sustenance is second-best. Cold drinks will cool you quickly. Don’t cook anything indoors—burning fuel creates carbon monoxide and an open flame (even candles) can start a fire. If you have a grill or manage to build a fire outdoors, and warm up in your safely parked car (read: not in a garage) before heading inside. You could try to cook in a well-ventilated fireplace, but these usually aren’t built for cooking and it could be difficult or dangerous to do so.

Stay away from alcohol—it might make you feel warm, but it lowers your core temperature and makes you more susceptible to hypothermia.

What to do when the power comes on

When it’s all over, think about what went well and what didn’t, and take it as a lesson to prepare for any future power outages or extreme weather. Climate change means worse hurricanes, more widespread fires, deadly heat waves, and far-reaching cold, all of which can take down overburdened or ill-prepared power grids.

And when your furnace rumbles back on, Otis recommends finding the exhaust port outside your home and making sure it’s not blocked. Even if it’s not clogged with snow, condensation can build up and freeze, forcing carbon monoxide back into your home just when you think it’s safe again.