A surprising statistic from the National Institute on Aging: roughly 20% of cold-related injuries happen inside the home — not stranded on a road, not caught outdoors, but sitting in a house that’s slowly losing heat. Winter power outages kill people two ways: the cold itself, and the well-intentioned but dangerous attempts to fight it — carbon monoxide from generators or grills run indoors, house fires from unattended space heaters or candles. This guide covers both problems: how to actually retain and generate heat safely, and the specific mistakes that turn a cold house into a fatal one.
The Safe Heat Sources (In Order of Preference)
1. Your existing fireplace or wood stove, if you have one and it’s up to code. CDC guidance lists this first among alternate heat sources — a properly functioning, code-compliant fireplace or wood stove with dry firewood is a legitimate primary heat source during an outage [→ /outage-prep/power-outage-checklist/]. Never leave it unattended, and keep anything flammable at least 3 feet away, per Red Cross guidance.
2. A generator powering your existing furnace. Even a modest generator running just your furnace’s blower motor (typically 500–800W) restores your home’s actual heating system rather than improvising a substitute [→ /standby-generators/what-size-generator-do-i-need/]. This is usually the most effective single move available to generator owners, and it’s precisely why furnace blower load appears near the top of every sizing guide on this site [→ /portable-generators/generator-wattage-chart/].
3. A space heater — with real caution. CDC and Red Cross guidance both permit space heater use but with specific rules: 3 feet of clearance from anything flammable, never left unattended, never used with an extension cord unless explicitly rated for it, and — if powered by a generator — properly accounted for in your load calculation (resistance heaters draw 1,500W continuously, a serious chunk of a portable generator’s capacity) [→ /portable-generators/generator-wattage-chart/].
4. Extra layers, blankets, and sleeping bags — the zero-risk option. CDC guidance explicitly lists this as a legitimate heat source, not just a supplement: dressing warmly indoors (including a head covering — a meaningful amount of body heat is lost through the head), using sleeping bags, and layering blankets works, costs nothing, and carries no fire or CO risk whatsoever.
What NOT to Use for Heat (This Section Saves Lives)
Never use a generator, gas or charcoal grill, or camp stove indoors — including the garage, even with the door open. This is CDC guidance stated as plainly as official sources ever state anything, because carbon monoxide poisoning is genuinely common during winter power outages specifically from people using these devices to generate heat indoors [→ /portable-generators/portable-generator-safety-carbon-monoxide/]. Generators belong at least 20 feet from any window, door, or vent, in a spot protected from snow and rain reaching the unit.
Never use a gas stove or oven for heat. This is one of the most common and most dangerous winter outage mistakes — gas ranges aren’t designed for sustained operation as heaters and produce dangerous carbon monoxide levels when run that way.
Never use candles as your primary light or heat source. Both CDC and Red Cross guidance specifically flag candles as a fire risk during outages — battery-powered flashlights and lanterns are the recommended alternative, and if candles are used at all, never leave them unattended [→ /outage-prep/best-emergency-lighting-power-outages/].
Install a battery-operated carbon monoxide detector if you don’t already have one. This is explicit CDC guidance, not an optional add-on — CO detectors need battery backup precisely because they matter most during the power outages that make CO poisoning more likely in the first place [→ /portable-generators/portable-generator-safety-carbon-monoxide/].
Zone Heating: Retaining Warmth Without Any Additional Heat Source
Before or alongside generating heat, retaining what warmth exists matters enormously — this costs nothing and works immediately:
1. Close off unused rooms entirely. Concentrate everyone in one or two rooms rather than trying to heat the whole house — CDC guidance specifically recommends this “zone heating” approach.
2. Stuff towels or rags in door gaps. The gap under an interior or exterior door is a genuine draft source; blocking it is a two-minute task with real effect.
3. Cover windows with blankets at night. Windows lose heat far faster than insulated walls — covering them, especially after dark, measurably reduces heat loss in the room you’re occupying.
4. Avoid unnecessarily opening doors or windows. Obvious, but worth stating: every trip outside or draft from an opened door lets accumulated warmth escape.
5. Keep everyone together. Beyond the social/morale benefit, body heat in a small, closed-off space is a genuine (if modest) contribution to the room’s temperature.
Protecting Your Pipes (The Damage That Outlasts the Outage)
Frozen and burst pipes are frequently more expensive and disruptive than the outage itself — American Red Cross guidance treats pipe protection as a parallel priority to staying warm, not an afterthought:
1. Let faucets drip — even a trickle. Running water, even minimally, meaningfully reduces freezing risk in exposed or vulnerable pipes. This is specifically effective for faucets served by pipes running along exterior walls or through unheated spaces.
2. Open cabinet doors under sinks. This lets whatever heated air remains in the house circulate around the plumbing beneath kitchen and bathroom sinks — a real, zero-cost precaution per both CDC and Red Cross guidance.
3. Keep the garage door closed if water lines run through the garage. Garages are often unheated and exposed; closing the door retains what warmth exists in that space.
4. If you’re leaving the house during the outage, keep the heat on at whatever level you can sustain — Red Cross guidance specifically recommends no lower than 55°F if the home will be unoccupied during cold weather with any heat source still available.
5. If a pipe does freeze: never thaw it with an open flame or torch — this is explicit CDC guidance, since it risks fire and pipe damage. Keep the affected faucet open as you address the frozen section, since running water helps as ice begins to melt.
6. If you have exposed, vulnerable pipes and no heat source at all during a genuinely extended, severe cold event, shutting off the main water valve is a more aggressive precaution worth considering — it prevents the flooding that follows a burst pipe, at the cost of no running water until you turn it back on.
When to Leave the House
Sometimes the honest answer isn’t “how do I stay warm here” — it’s “should I be here at all.” Red Cross guidance is direct about this: if the power is out with no heat source and cold is genuinely dangerous (especially with elderly household members, infants, or anyone with health conditions), plan where you’d go — a relative’s home, a friend’s, or a public warming shelter, which many communities open during serious winter outage events. Deciding this early, before conditions deteriorate further, beats deciding it under duress.
Ask someone to check on you during serious cold events, particularly if anyone in the household is elderly or has health vulnerabilities — this is specific Red Cross guidance for winter outages, not general advice.
Frequently Asked Questions
What’s the safest way to heat a house without power? In order of safety and effectiveness: a code-compliant fireplace or wood stove, a generator powering your existing furnace, a properly-supervised space heater with 3 feet of clearance from flammables, and — with zero risk — extra layers, blankets, and zone heating to retain existing warmth.
Can I use my gas stove to heat my house during an outage? No — this is a genuinely dangerous and surprisingly common mistake. Gas ranges aren’t designed for sustained heating use and produce dangerous carbon monoxide levels when operated that way.
How do I keep my pipes from freezing during a power outage? Let faucets drip, open cabinet doors under sinks to circulate warm air around plumbing, keep the garage closed if water lines run through it, and if you must leave the house, maintain heat at 55°F or above if any heat source remains available.
Is it safe to run a generator in the garage during winter if the door is open? No — this is one of the most common and most dangerous winter outage mistakes. Generators must be at least 20 feet from any window, door, or vent, regardless of weather or garage door position [→ /portable-generators/portable-generator-safety-carbon-monoxide/].
How can I heat my house without electricity or a generator? A code-compliant fireplace or wood stove is the most effective zero-electricity option. Beyond that, zone heating (closing off rooms, blocking drafts, covering windows) plus layered clothing and blankets retains and makes the most of whatever ambient warmth remains.
When should I leave my house during a winter power outage? When no safe heat source is available and cold conditions are genuinely dangerous — especially with elderly residents, infants, or health-vulnerable household members present. Plan a destination (relative, friend, or public warming shelter) before conditions worsen rather than deciding under pressure.