When the Power Goes Out
Safe warmth when the furnace stops.
Most heating systems require electricity. When the power goes out in winter, the house begins losing heat immediately. The decisions you make in the first few hours determine whether the outage is uncomfortable or dangerous.
By Dan Whelan, founder of New World Survival
Researched from government agencies, university extension services, and other published sources. See our sources
The Physics
How fast your house loses heat
Your home is a thermal battery. Once the furnace stops, it begins discharging heat through walls, windows, the roof, and air leaks. How fast it discharges depends on insulation quality, construction age, window type, outdoor temperature, and wind. Understanding the timeline helps you plan rather than react.
| House type | Approx. loss per hour | 68 to 50 degrees F | 68 to 40 degrees F | 68 to freezing |
|---|---|---|---|---|
| Well-insulated (post-2000, good air sealing) | 1 to 2 degrees F | 9 to 18 hours | 14 to 28 hours | 18 to 36 hours |
| Average (1970s to 1990s, standard insulation) | 2 to 3 degrees F | 6 to 9 hours | 9 to 14 hours | 12 to 18 hours |
| Poorly insulated (pre-1970, single-pane windows) | 3 to 5 degrees F | 3 to 6 hours | 5 to 9 hours | 7 to 12 hours |
| Mobile / manufactured home | 4 to 7 degrees F | 2 to 4 hours | 4 to 7 hours | 5 to 9 hours |
Estimates assume outdoor temperature in the low 20s F with moderate wind. Actual rates vary with solar exposure, wind speed, and occupancy. Interior rooms with closed doors cool slower than rooms with exterior walls.
What drives the rate
Heat escapes through conduction (walls, roof, floor, windows), convection (air leaks around doors, windows, outlets, and recessed lights), and radiation (single-pane windows radiate heat outward). A single-pane window loses heat roughly ten times faster than an insulated wall of the same area. The attic and crawlspace are the next largest loss paths. Wind accelerates all three by stripping the warm-air boundary layer off exterior surfaces and forcing cold air through gaps.
The temperature thresholds that matter
55 to 60 degrees F: Uncomfortable but safe for healthy adults with appropriate clothing. Decision point: assess your heating options and make a plan. 50 degrees F: Sustained exposure at rest is a hypothermia risk for elderly adults, infants, and people with certain medical conditions. 40 degrees F: All household members are at risk without active warming. Pipes in exterior walls begin freezing in some houses. 32 degrees F: All exposed plumbing is at risk. Unsafe for prolonged occupancy without a functioning heat source.
Immediate Actions
The first hour without heat
Every action in the first hour buys time. The house is still warm. Your body is still warm. Use this window to set up the conditions that will keep you comfortable or safe for hours or days, depending on what you have available.
Choose your warm room
Pick one room and move everyone into it. The best choice is an interior room on the ground floor with few or no exterior walls, small windows, and a door that closes. An interior bathroom, hallway, or small bedroom works well. Avoid rooms with cathedral ceilings (heat rises and pools uselessly), large picture windows (massive heat loss), or rooms above unheated garages or crawlspaces. If you have a wood stove or fireplace, that room is the obvious choice regardless of other factors.
Seal and insulate
Close every interior door. Stuff towels or rolled blankets under the gaps of rooms you are not using. Close all blinds and curtains in every room. In the warm room, hang quilts, blankets, or even heavy coats over windows. A single-pane window can lose heat ten times faster than an insulated wall. Covering it with any dense fabric slows the loss substantially. If you have plastic sheeting or even large garbage bags, taping them over windows adds a dead-air layer that measurably reduces convective loss.
Layer up before you feel cold
Put on layers now, while you are still comfortable. The human body produces roughly 80 to 100 watts of heat at rest. Trapping that heat with layers is the simplest, most reliable, and most overlooked warming strategy. Wear a base layer (synthetic or wool, not cotton), an insulating mid layer (fleece, wool sweater, or down vest), and a wind-blocking outer layer if the house is drafty. Cover your head, which accounts for significant heat loss. Wool socks and insulated slippers matter more than most people expect. Cotton loses its insulating value when damp from sweat; wool and synthetic fleece do not.
Protect the pipes
Open cabinet doors under sinks on exterior walls so room air reaches the pipes. If you have running water, let a thin trickle flow from one faucet served by an exposed pipe. Moving water resists freezing. A cold drip, slightly more than one drop per second, is sufficient. If temperatures will stay below 20 degrees F and the outage may last more than a few hours, consider shutting off the main water valve and draining the system. See the pipe protection section below for full detail.
Stage your warm room
Gather everything you will need before the rest of the house gets cold. Moving through a 40-degree house later to retrieve forgotten items is miserable and wastes body heat. Bring: sleeping bags and blankets for everyone, flashlights and headlamps, water bottles, snacks and easy-to-eat food, all medications, phone chargers and a battery pack, a battery-powered radio, books or games for children, pet supplies, and your CO detector if it is not already in the room. If you have a portable indoor-rated heater, set it up now.
Assess your timeline
Check with your utility for an estimated restoration time. Check the weather forecast for the next 24 to 48 hours. If temperatures will remain below freezing and restoration is uncertain, begin planning your evacuation option now, while roads are still passable and warming shelters have space. The decision to leave gets harder every hour you wait. Making it early, while you are warm and have daylight, is almost always better than making it at midnight when the house is 45 degrees and the roads have iced over.
Safe Options
Indoor heating sources rated by safety
Not every heat source belongs indoors. The wrong choice produces carbon monoxide, a colorless, odorless gas that kills. The CPSC reports that from 2010 to 2020, non-fire CO poisoning deaths from consumer products trended upward, reaching an estimated 254 deaths in 2019. Generators and portable heaters were the two leading product categories.[1] Separately, space heaters and heating stoves account for about 30 percent of home heating fires but 73 percent of heating fire deaths, according to the NFPA.[2]
This section lists only heating methods that are safe for indoor use when properly set up and operated. Each entry includes the safety requirements, because those requirements are not optional.
| Heat source | BTU output | Heats (sq ft) | Runtime | Fuel cost | Combustion? | CO risk |
|---|---|---|---|---|---|---|
| Wood stove / fireplace insert | 25,000 to 80,000 | 1,000 to 2,500 | 4 to 10 hrs per load | $250 to $400/cord | Yes (vented) | Low (if chimney is clear) |
| Electric space heater (via generator/battery) | 5,100 (1,500W) | 150 to 250 | Fuel or battery dependent | Generator fuel | No (indoors) | None (indoors) |
| Indoor-rated propane heater (with ODS) | 4,000 to 18,000 | 100 to 450 | 3 to 6 hrs per 1-lb cylinder | $4 to $6 per cylinder | Yes (unvented) | Low (ODS shuts off) |
| Generator powering the furnace | Full furnace output | Whole house | 6 to 12 hrs per tank | $15 to $30/day in fuel | Yes (outdoors only) | High if placed wrong |
| Kerosene heater (where legal, vented) | 10,000 to 23,000 | 250 to 600 | 8 to 12 hrs per fill | $5 to $8 per gallon 1-K | Yes (unvented) | Moderate (requires ventilation) |
Wood stove or fireplace insert
A properly installed wood stove with a functioning chimney is the most effective non-electric heating option for a winter outage. A modern EPA-certified stove can heat an entire small house on a single load of seasoned hardwood. The key requirements: the chimney must be clean and inspected annually, the stove must have proper clearances from combustible materials (typically 36 inches to the side and rear, 18 inches in front, as specified by the manufacturer and NFPA 211), and you need seasoned firewood (split, stacked, and dried for 6 to 12 months with moisture content below 20 percent).[3]
A traditional open fireplace is far less efficient than a stove or insert. It draws room air up the chimney and can actually make other rooms colder. A fireplace insert, which fits into an existing fireplace opening with a sealed firebox and heat-exchange tubes, converts an open fireplace into an effective heater.
Never burn treated lumber, painted wood, plywood, particleboard, or trash in a wood stove. These release toxic fumes and accelerate creosote buildup. Keep a fire extinguisher within reach. Our wood heat guide covers stove selection, fuel, chimney systems, and safety in depth.
Electric space heater with generator or portable power station
If you have a generator or a large portable power station, an electric space heater is the safest indoor option because it produces no combustion byproducts. A standard ceramic heater draws 1,500 watts and puts out approximately 5,100 BTU, enough to warm a small bedroom. Choose one with a tip-over shutoff and overheat protection. Keep it at least 3 feet from anything flammable. Never plug a space heater into an extension cord, power strip, or surge protector. Plug it directly into a wall outlet powered by the generator circuit.
The generator must be outdoors, at least 20 feet from any door, window, or vent, with exhaust directed away from the house.[4] Run a heavy-duty outdoor-rated extension cord (12-gauge or heavier for 1,500W loads) through a cracked window or door. A portable power station rated at 2,000Wh or above can run a 1,500W heater for roughly one hour, or a smaller 750W heater for about two hours. This is a supplemental strategy, not a primary heating plan for a multi-day outage.
See our generator guide and portable power station guide for sizing and setup.
Indoor-rated propane heater with oxygen depletion sensor
Some portable propane heaters are specifically designed, tested, and rated for indoor use. The critical features to verify on the label: "indoor safe" or "indoor use" rating, an oxygen depletion sensor (ODS) that automatically shuts the unit off if oxygen levels drop, and a tip-over shutoff. A typical 9,000-BTU indoor-rated propane heater can warm a 200 to 250 square foot room. A larger 18,000-BTU model can handle a 400 to 450 square foot space.
Even with an ODS, always ensure some ventilation. Crack a window in the room at least one inch. Place a working battery-powered CO detector in the room. Use only the 1-pound propane cylinders designed for the heater, or connect to a 20-pound tank through the manufacturer's hose and regulator kit. Do not modify the fuel connection. A single 1-pound cylinder provides 3 to 6 hours of heat depending on the BTU setting.
If the heater label does not say "indoor use" and does not list an ODS, it is not safe indoors regardless of the brand name.
Generator powering the furnace
A portable generator of 2,500 to 3,500 watts (to handle the blower motor's startup surge) can power most residential gas furnaces. This is the only option that keeps your existing central heating system running. The generator stays outdoors, at least 20 feet from any door, window, or vent, with exhaust pointed away from the house.[4]
Connect through a transfer switch installed by a licensed electrician, or use a heavy-duty outdoor-rated extension cord (10-gauge minimum for furnace loads). Never backfeed power into your breaker panel by plugging a generator into a wall outlet or wiring it directly to the panel without a transfer switch. Backfeeding can electrocute utility workers repairing lines and can damage your electrical system when grid power returns.
See our generator guide for transfer switch options and sizing.
Kerosene heater (where legal, with ventilation)
Kerosene heaters produce strong radiant heat (10,000 to 23,000 BTU) and can run 8 to 12 hours on a single fill. However, they burn fuel indoors without a flue, which means they consume oxygen and produce CO, CO2, nitrogen dioxide, and water vapor. Some states and many municipalities prohibit unvented kerosene heaters. Check your state and local fire codes before purchasing one.
If legal in your area and you choose to use one: buy only models rated for indoor use with a UL listing. Use only 1-K grade kerosene (clear, not red-dyed). Refuel outdoors only, after the heater has cooled. Crack a window at least one to two inches in the room where the heater operates. Place a battery-powered CO detector in the room. Keep the heater at least 3 feet from all combustible materials. Never leave it running while you sleep.
Kerosene can be difficult to source during a regional outage. If you plan to rely on a kerosene heater, stock fuel before winter. Store kerosene outdoors in approved containers, away from the house, and rotate your supply annually. Old kerosene gels and clogs wicks.
The Invisible Killer
Carbon monoxide: the rules that save lives
Carbon monoxide (CO) is produced whenever fuel burns: gasoline, propane, natural gas, wood, charcoal, kerosene. It is colorless and odorless. You cannot see it, smell it, or taste it. CO poisoning can cause unconsciousness within minutes and death shortly after. The CPSC reports that since 2010, portable generators alone have been linked to an estimated 796 non-fire CO poisoning deaths. The majority occur during winter, during power outages, when people bring generators, grills, or outdoor heaters inside to stay warm.[1]
Never use these indoors for heat
Portable generator. Not in the house, garage, basement, crawl space, or shed. Not with the door open. Not on a porch or carport. At least 20 feet from any opening, exhaust pointed away.[4]
Charcoal grill or hibachi. Charcoal produces extreme CO levels. A single hibachi in an enclosed room can reach lethal CO concentration within an hour. People die from this every winter.
Propane or gas camp stove. Designed for outdoor or well-ventilated use only.
Gas oven. Not designed for space heating. Produces CO during normal combustion. The CPSC specifically warns against using a gas oven for heat.
Any propane heater without an ODS label. If it does not say "indoor use" and does not have an oxygen depletion sensor, it belongs outside.
Kerosene heater in a sealed room. Even indoor-rated kerosene heaters require a window cracked for ventilation and a working CO detector.
CO detectors save lives
Install battery-powered CO detectors on every level of your home and outside each sleeping area. Test monthly. Replace batteries at least annually and the detector itself every 5 to 7 years (check the manufacturer date on the back). During a power outage, hardwired CO detectors may not work unless they have battery backup. A battery-operated detector is your last line of defense.
If you use any fuel-burning heat source during an outage, place a CO detector in the same room, at breathing height, between the heat source and the sleeping area.
CO poisoning symptoms
Headache, dizziness, weakness, nausea, vomiting, chest pain, and confusion. Because these symptoms resemble the flu, people often do not recognize CO poisoning until it is severe. The critical difference: flu does not cause dizziness and confusion, and flu affects household members on different timelines. If everyone in the house feels sick at the same time, suspect CO.[5]
If the CO alarm sounds or multiple people are symptomatic: Get everyone outside immediately. Call 911 from outdoors. Do not re-enter to search for the source. Do not open windows to "air it out" and go back inside. Leave and let the fire department handle it.
Heat Retention
Keeping the heat you already have
Even without a dedicated heat source, you can meaningfully slow how fast your house cools. Every degree you retain extends your comfort window and your decision window. These strategies cost nothing and work immediately.
The one-room strategy
Four people in a small room with the door closed, windows covered, and a blanket over the gap under the door can maintain a room temperature 10 to 15 degrees above the rest of the house through body heat alone. This is not a metaphor. The average adult at rest produces 300 to 400 BTU per hour. Four adults produce 1,200 to 1,600 BTU per hour, equivalent to a small electric heater. A small room with low ceilings and good insulation will hold that heat.
The warm room should have access to a bathroom if possible. If not, keep a path to the nearest bathroom and return to the warm room promptly. In a house with central air returns, stuff the return vents in your warm room with towels to prevent cold air from the ductwork from flowing in.
Sleeping warm without heat
Insulate below as much as above. You lose as much heat through the surface you lie on as through the air above you. A camping pad, yoga mat, folded blankets, or even couch cushions on the floor create a barrier between your body and the cold floor. Then layer sleeping bags or blankets on top. A sleeping bag rated to 30 or 40 degrees F is more than adequate for indoor use at 50 degrees F.
Sleep in dry layers, including a hat and socks. Zip children into their own sleeping bags rather than sharing adult bags, which tend to leave gaps. Put infants in wearable sleep sacks with additional blankets over the sack, but never over their face. If two adults share a sleeping area, body heat transfer is significant, especially in a sleeping bag designed for two.
Avoid alcohol before sleeping in a cold house. Alcohol dilates blood vessels, which makes you feel warmer temporarily but increases actual heat loss and impairs your body's cold-sensing ability.
Hot water bottles and hand warmers
If you can boil water (camp stove outdoors, wood stove, or generator-powered kettle), a hot water bottle or a tightly sealed container of hot water wrapped in a towel provides direct body heat for 2 to 4 hours. Place it at your core (chest, abdomen) or feet for maximum warming effect.
Disposable chemical hand warmers (iron-powder activated type) provide 8 to 12 hours of steady warmth and cost roughly $1 per pair. Place them inside gloves, shoes, or a pocket against your body. They are safe for overnight use in a sleeping bag at your feet or lower back. Stock a box of 20 to 40 pairs before winter as part of your heating outage kit.
Use daytime solar gain
If the sun is out during the day, open curtains on south-facing windows to let solar radiation warm the room. Even in winter, direct sunlight through glass can raise a room's temperature by 5 to 10 degrees during peak sun hours. Close the curtains again before sunset to retain the gained heat. This costs nothing and works even in very cold weather as long as the sky is clear. Our passive heating and cooling guide covers this approach in depth.
The Car Option
Using your vehicle to warm up
Running the car heater for short sessions is a legitimate warming strategy during a power outage, and many people do it. It is also the source of CO deaths every winter when people run vehicles in enclosed spaces. The rules are non-negotiable.
Safe use
The vehicle must be outdoors in open air, not in a garage (even with the door open). Clear snow away from the exhaust pipe before starting the engine. Carbon monoxide from a blocked or partially blocked exhaust can enter the cabin. Keep a window cracked slightly. Limit sessions to 15 to 20 minutes to conserve fuel. Bring blankets and a phone. This is a supplemental warming method, not a primary heating plan.
Never in a closed garage
A running car in a closed garage can fill the space with lethal CO levels in under 10 minutes. An attached garage can push CO into the house through shared walls, doors, and ductwork even when the connecting door is closed. This kills people every year. If your car is in an attached garage and you want to use it for heat, pull it outside first with the garage door fully open, then close the garage door before sitting in the car with the engine running.
Fuel conservation
A typical car idles at about 0.3 to 0.5 gallons per hour. In a regional outage, gas stations may be closed or have long lines. Ration your fuel. Warm the car, warm yourselves, then turn it off and return to the house. Repeat as needed. A half tank of gas gives you 8 to 12 warming sessions before you need to refuel. Keep the tank above half during winter storm season.
What Does Not Work
Dangerous myths and bad advice
Every winter, social media and well-meaning forwarded messages circulate heating "hacks" that range from useless to deadly. If a heating method sounds too simple and too cheap to be real, it probably is. Here are the ones that keep showing up.
The terracotta pot candle heater
A clay flower pot inverted over candles does not meaningfully heat a room. A single candle produces about 80 watts of heat. The pot absorbs and re-radiates that heat, but it does not amplify it. The total output is equivalent to a human body at rest. Meanwhile, the assembly is a fire hazard: the pot can crack from thermal stress, and grouped candles can overheat the surface beneath them. Several house fires have been attributed to these devices. They are not a heating solution.
"Just crack a window" with a generator
Cracking a window does not make it safe to run a generator indoors. A portable generator can produce as much CO as hundreds of cars. No amount of window-cracking provides sufficient ventilation. The generator must be at least 20 feet from the house, outdoors, with no enclosure. This misconception kills people every year, and the CPSC has issued specific warnings against it.[4]
"The oven will keep us warm"
A gas oven is not a space heater. It is not designed for continuous operation with the door open. Gas ovens produce CO during normal combustion, and running one for hours in a closed house can build CO to dangerous levels. The CPSC explicitly warns against this practice. Electric ovens are inefficient space heaters and present a burn and fire hazard when left open.
"I ran the generator in the garage last time and we were fine"
CO poisoning is dose-dependent. Previous exposure without symptoms does not mean the next exposure will be safe. Wind direction, garage door gap width, temperature differentials, and run time all affect CO accumulation. The fact that it did not kill you last time is survivorship bias, not evidence of safety.
Alcohol to "warm up"
Alcohol makes you feel warmer by dilating blood vessels near the skin, which gives a sensation of warmth. But it actually increases heat loss from the body's core by moving blood to the surface, where it loses heat faster. It also impairs your ability to sense when you are dangerously cold and disrupts shivering, which is your body's primary heat-generation mechanism. In a cold house, alcohol makes hypothermia more likely, not less.
Your Situation
Heating by housing type
Not everyone has a wood stove and a generator in the garage. Your options depend on where you live, what you rent or own, and what your building allows. Here is what works for each situation.
Apartment and condo
Generators are typically not an option. No chimney means no wood heat. Your practical options: an indoor-rated propane heater with ODS (check your lease and local fire codes, as some buildings prohibit open-flame devices), layers, blankets, the one-room strategy, hand warmers, and hot water bottles if you have a way to heat water. Apartments in multi-unit buildings benefit from shared walls, which provide insulation from neighbors' heat. An interior unit with neighbors on all sides stays warmer longer than a corner unit.
If the building has a lobby, community room, or common area with backup heat, check whether it is open. Many apartment complexes designate warming areas during extended outages. Know your building's plan before you need it. Our renter preparedness guide covers more detail.
Mobile and manufactured home
Manufactured homes cool faster than site-built houses due to thinner walls, less thermal mass, less insulation, and more air leakage, especially around windows, doors, and the floor. A mobile home that starts at 68 degrees can reach 50 degrees in 2 to 4 hours when it is 20 degrees outside. Every minute of preparation matters more here.
Many mobile homes have underbelly insulation that sags or is damaged, allowing cold air to reach floor-level pipes and the floor itself. If you can access the skirting, check it. A damaged underbelly panel lets wind through. An indoor-rated propane heater is often the best option for manufactured homes. Keep a CO detector running and ventilate. Plan to leave earlier than you would in a site-built house. Your margin is smaller.
Single-family home with fireplace or stove
You have the widest range of options. A wood stove or fireplace insert is your primary heat source. Close off the rest of the house and keep the family in the room with the stove. If you have a generator, you can also run the furnace. For supplemental heat in other rooms (bathrooms, for example), an indoor-rated propane heater works well.
Your primary preparation task, before any outage: have the chimney inspected and cleaned annually. Stock at least one cord of seasoned firewood (more if wood is your primary backup plan). Keep your generator maintained, fueled, and tested. Have a transfer switch installed if you plan to power the furnace. These are all things that cannot be done during the outage.
Rural property with no natural gas
Many rural homes rely on propane, fuel oil, or electric heat pumps, all of which require electricity for fans, pumps, or ignition. Without power, these systems do not work. A wood stove is the standard rural backup, and many rural homes already have one. If yours does not, consider installing one. For propane-heated homes, keep the tank above 30 percent heading into winter. A generator that can power the furnace blower is the next priority. Extended rural outages can last a week or more after ice storms because utility crews prioritize high-density areas first.
Protect the House
Preventing frozen and burst pipes
A burst pipe from freezing can cause $5,000 to $70,000 in water damage, depending on where it breaks and how long before it is discovered. During a winter outage, pipe protection is as important as personal warmth. Water expands by about 9 percent when it freezes, and the pressure can split copper, PVC, and PEX pipes.
Most vulnerable pipes
Pipes in exterior walls, unheated garages, crawl spaces, attics, and near exterior hose bibs. Pipes in interior walls are generally safe as long as the house stays above freezing. The risk increases sharply when air temperature around the pipe drops below 20 degrees F and stays there for several hours. PEX is more freeze-resistant than copper (it can expand somewhat before splitting), but it is not freeze-proof.
If you have running water
Open cabinet doors under sinks on exterior walls. Let a thin trickle of water run from one or two faucets served by the most exposed pipes. Moving water resists freezing. A cold trickle, slightly more than one drop per second, is sufficient. Set both hot and cold lines to drip if possible. The cost of running water is negligible compared to a burst-pipe repair.
If you are leaving the house
If you evacuate to a warmer location, shut off the main water valve and drain the system. Open all faucets, flush toilets, and drain the water heater if it is safe to do so and the heater is off. This removes the water that would freeze and burst the pipes. When power returns and you come home, close faucets, open the main valve slowly, and check for leaks before restoring full pressure. Know where your main shutoff is before you need it. Our utility shutoffs guide covers the location, operation, and testing of all three household shutoffs.
If a pipe freezes but has not burst
Open the faucet served by the frozen pipe. Apply gentle heat to the frozen section using a hair dryer (if you have power), warm towels, a portable space heater directed at the area, or heat tape. Start from the faucet end and work toward the frozen section. Never use an open flame, propane torch, or blowtorch on a frozen pipe. The pipe can burst from steam pressure, or nearby materials can catch fire. If a pipe has burst, shut off the main water valve immediately and call a plumber.
Recognize the Danger
Recognizing hypothermia and frostbite
Hypothermia can develop indoors. A house at 50 degrees F with a person who is elderly, sedentary, inadequately dressed, or damp is a hypothermia risk. You do not need to be outdoors in a blizzard. The CDC defines hypothermia as a body temperature below 95 degrees F, and notes that older adults can develop hypothermia inside their own homes.[6]
Hypothermia
Early signs: Shivering, confusion, slurred speech, drowsiness, loss of coordination, fumbling hands.
Late signs: Shivering stops (a danger sign, meaning the body has exhausted its ability to generate heat), stiff muscles, very slow breathing, loss of consciousness.
In infants: Bright red, cold skin and very low energy.
Response: Call 911. Move to a warm area. Remove wet clothing. Warm the center of the body first: chest, neck, head, groin. Use blankets, sleeping bags, or skin-to-skin contact under dry blankets. Give warm (not hot) beverages if conscious and alert. Do not give alcohol. Do not rub extremities. Handle gently to avoid triggering cardiac arrhythmia.
Frostbite
Frostnip (reversible): Red or pale skin, tingling, numbness in fingers, toes, nose, ears, or cheeks.
Frostbite (tissue damage): White or grayish-yellow skin, hard or waxy texture, complete numbness, blistering after rewarming.
Response: Move indoors. Do not rub the affected area. Rubbing damages frozen tissue. Immerse in warm (not hot) water, 100 to 104 degrees F, or apply warm cloths. Do not use direct heat (heating pad, fire, stove) because frostbitten skin burns easily and the person may not feel it. Seek medical attention for any frostbite beyond frostnip.[7]
Who is most vulnerable
Adults over 65 (reduced ability to sense cold and regulate body temperature), infants and young children (lose body heat faster relative to body mass), people with chronic conditions (heart disease, diabetes, thyroid disorders, Parkinson's disease), people using certain medications (sedatives, psychiatric medications, beta-blockers), people who have consumed alcohol (increases heat loss while reducing cold awareness), and anyone who is wet, exhausted, or malnourished. If any of these describe a household member, your decision threshold for leaving should be earlier and at a higher indoor temperature.
Extended Outages
When the outage lasts days
Most outages end within a few hours. Some do not. Ice storms, derechos, and severe winter weather have caused regional outages lasting a week or more in the past decade. The priorities shift as time extends. Here is what changes.
Immediate response
Execute the first-hour protocol above. Deploy your heat source. Protect pipes. Consolidate to one room. Eat available food. Conserve phone battery. Check on neighbors, especially elderly residents living alone. Report the outage to your utility. Listen to battery-powered radio or check local news for restoration estimates.
Settling in or leaving
Assess food and fuel supply. Refrigerator food is no longer reliably safe if the fridge has been without power for 4 or more hours (see our refrigerator guide). If you are staying, move perishable food to a cooler or outdoors if temperatures are below 40 degrees F. Ration generator fuel. If restoration is not expected within 24 more hours and you have vulnerable household members, this is the decision point to leave.
Fuel and morale
Fuel becomes the limiting factor. A portable generator uses 8 to 15 gallons per day at half load. If gas stations are closed, your supply is finite. Ration use: run the generator to heat the house for 2 to 3 hours, then shut it off and seal up. Firewood consumption also increases as temperatures stay low. Plan meals around what you have. Boil water if municipal water is compromised (a common secondary effect of extended outages). Maintain routines, especially for children. Boredom and cold together degrade morale faster than either one alone. Our extended outage guide covers the full timeline.
Reassess everything
If power has not been restored and your fuel, food, or water supply is running low, leave. This is not a judgment on your preparation. Some outages simply outlast what a household can sustain without utility-scale infrastructure. Call 211, check local emergency management for warming shelters, or go to family or friends with power. Before leaving, shut off the water main, drain the system, and secure the house.
The Decision
When to leave and where to go
Leaving a cold house for a warmer location is not a failure. It is the correct decision when staying becomes dangerous. Make the decision while you can still drive safely, while roads are passable, and before anyone in the household is in distress. Deciding to leave at midnight when the house is 42 degrees and the roads have iced over is a much worse position than deciding at 4 PM when it was 55 degrees and the roads were clear.
Decision triggers
Leave if: indoor temperature is below 50 degrees and falling with no heat source available, the outage is expected to last overnight or longer in below-freezing conditions, any household member is elderly, an infant, has a chronic condition, or is showing early signs of cold stress, you do not have fuel, food, or water to sustain another night, or road conditions are expected to deteriorate. Each of these alone is sufficient. You do not need all of them.
Where to go
Family or friends with power (call ahead and go early), a hotel or motel (book early because rooms fill fast during regional outages; do not wait until dark), a designated warming shelter (call 211, check local emergency management, or monitor local news), or a community building with backup heat. Some churches, libraries, and community centers open during cold emergencies.
Before you leave
Shut off the main water valve and drain the system if temperatures will drop below freezing. Unplug appliances to prevent a power surge when electricity is restored. Leave one light on so you can see from outside when power returns. Take: medications, important documents, phone chargers and battery packs, warm clothing and sleeping bags, food and water for 24 hours, pet supplies, and cash (card readers may not work).
Build the Capability
Before next winter
The best time to prepare for a winter outage is during mild weather when there is no urgency, equipment is in stock and not price-gouged, and you can test everything calmly.
Battery CO detectors
Install on every level and outside every sleeping area. Test monthly. Replace batteries annually and the unit every 5 to 7 years. This is the single most important winter-outage preparation.
Insulation and air sealing
Every dollar spent on insulation and air sealing slows heat loss during outages and reduces your heating bill the rest of the year. Weatherstripping, caulk, attic insulation, and outlet insulation pads are the highest-return improvements. Our weather readiness guide covers the details.
Generator or backup power
A generator (2,500 to 3,500 watts) that can power your furnace blower keeps the whole heating system running. A transfer switch installed by an electrician makes the connection safe and easy. See our generator guide and power measurement guide for sizing.
Sleeping bags and blankets
Keep enough sleeping bags or heavy blankets for every household member. Rated to 30 to 40 degrees F is sufficient for indoor use. Store them accessible, not buried in the attic or a closet you cannot reach in the dark.
Know your main water shutoff
Locate it now, label it, and make sure it turns. A seized shutoff valve is worse than none because it creates a false sense of security. Our utility shutoffs guide covers all three shutoffs every household member should know.
Fuel supply
If you have a wood stove, stock at least one cord of seasoned firewood before winter. If you heat with propane, keep the tank above 30 percent. If you plan to use an indoor-rated propane heater, stock 10 to 20 one-pound cylinders or a 20-pound tank with a hose adapter. If you have a generator, store fuel safely in approved containers, away from the house, rotated every 6 to 12 months with fuel stabilizer.
Hand warmers and hot water bottles
A box of 20 to 40 disposable hand warmer pairs costs $15 to $25 and provides 8 to 12 hours of warmth per pair. A good hot water bottle costs $10 to $15 and lasts years. Both are cheap insurance that works when nothing else is available.
Chimney inspection
If you have a wood stove, fireplace, or insert, have the chimney inspected and cleaned by a CSIA-certified chimney sweep annually. A dirty chimney is a chimney fire waiting for the first long burn of winter. Schedule the inspection in late summer or early fall when sweeps are least busy.[3]
Sources
- CPSC. "Stay Safe, While Staying Warm This Winter." February 2024. Reports upward trend in non-fire CO deaths 2010 to 2020, reaching 254 deaths in 2019. Generators (92 deaths in 2020) and portable heaters (33 deaths) were leading categories. cpsc.gov. Accessed September 2026.
- NFPA. "Safety with Heating Equipment." 2020 to 2024 data. An estimated average of 37,365 home heating equipment fires per year, resulting in 417 deaths, 1,260 injuries, and $1.2 billion in property damage. Space heaters accounted for 30 percent of fires but 73 percent of deaths. nfpa.org. Accessed September 2026.
- NFPA 211. "Standard for Chimneys, Fireplaces, Vents, and Solid Fuel-Burning Appliances." National Fire Protection Association. Covers clearance distances, inspection requirements, and installation standards. nfpa.org. Accessed September 2026.
- CPSC. "Portable Generator Safety." Recommends generators be operated outdoors, at least 20 feet from any door, window, or vent. cpsc.gov. Accessed September 2026.
- CDC. "Carbon Monoxide Poisoning: Prevention Tips." cdc.gov. Accessed September 2026.
- CDC. "Hypothermia: Stay Safe in Cold Weather." Defines hypothermia as body temperature below 95 degrees F. Notes older adults can develop hypothermia indoors. cdc.gov. Accessed September 2026.
- CDC. "Frostbite: Prevention and Treatment." Covers rewarming protocols and when to seek medical attention. cdc.gov. Accessed September 2026.
- Ready.gov. "Power Outages." Federal guidance on preparing for and responding to power outages. ready.gov. Accessed September 2026.
- CPSC. "As Winter Storms Threaten Millions." December 2025. Reports approximately 100 generator-related CO deaths per year. cpsc.gov. Accessed September 2026.
Keep Going
Related guides
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Stoves, inserts, pellet stoves, firewood, chimney systems, and safety. The complete wood heat guide.
Passive heating and cooling
No-power strategies for thermal comfort: solar gain, thermal mass, ventilation, and insulation.
Power outage action plan
The complete step-by-step for the first hour, first day, and extended outage.