Carbon monoxide is what actually kills people
Start here, because it is the single most useful thing on this page. After a winter storm knocks the power out, the deaths that follow are disproportionately from carbon monoxide, not from cold. The pattern is always the same: the heat is off, someone brings a heat or power source indoors, and the exhaust has nowhere to go.
Never run a portable generator inside a house, a basement, a crawlspace, a shed, or an attached garage, including with the garage door open. Never bring a charcoal or gas grill indoors. Never use a camp stove or a propane heater not rated for indoor use inside a living space. Never heat a house with a gas oven with the door hanging open. A generator belongs well away from the building, far from any window, door or vent, with the exhaust pointed away.
Carbon monoxide has no smell, no color and no taste. There is no sense you own that will warn you, and the early symptoms — headache, nausea, dizziness, sleepiness — are exactly what a cold, stressed, badly slept person expects to feel anyway. A CO alarm is the detector. Put one on every level of the house and outside sleeping areas, test them, and replace them on the schedule printed on the unit, because the sensors expire whether or not the battery does. If an alarm sounds, get everyone outside into fresh air first and call 911 from there. Do not stay inside hunting for the source. If you are sizing backup power, the generator sizing calculator covers the electrical side; the placement rule above is not negotiable regardless of size.
Reading a cold forecast
The National Weather Service issues winter products on the same watch-and-warning logic as everything else: a watch means severe conditions are possible and you should prepare, a warning means they are occurring or imminent. Names and criteria differ by region — what triggers a warning in Minnesota does not resemble what triggers one in Georgia, deliberately, because the infrastructure and the population are not the same. Check weather.gov for your own office rather than carrying a number in your head.
Wind chill is worth understanding rather than memorizing. It is not a temperature the thermometer would read; it is an estimate of how fast exposed skin loses heat with wind added. It matters for people and animals and not at all for pipes, which freeze on air temperature alone.
Hypothermia and frostbite
| Hypothermia | Frostbite | |
|---|---|---|
| What it is | Core body temperature dropping | Tissue freezing, usually fingers, toes, ears, nose, cheeks |
| Early signs | Hard shivering, clumsiness, slurred speech | Numbness, pins and needles, waxy pale or grayish skin |
| Serious signs | Shivering stops, confusion, drowsiness, collapse | Skin hard to the touch, blisters, loss of all sensation |
| What to do | Call 911, get indoors, remove wet clothing, wrap in dry blankets, warm the trunk first | Get indoors, rewarm in warm — not hot — water, protect the area |
| Do not | Give alcohol; rub the limbs hard; plunge into hot water | Rub or massage; use a heater or fire directly; break blisters |
The counterintuitive part of hypothermia is that things look calmer as they get worse. Violent shivering is the body still fighting. When the shivering stops and the person becomes quiet, agreeable and sleepy, they have gotten worse, not better. Alcohol makes all of this more likely by opening surface blood vessels while making people feel warm, which is why falling asleep outdoors after drinking is the classic path to a cold death.
With frostbite, warm water at bath temperature is the right tool and a heater is not, because the tissue has no sensation and will burn without complaint. If there is any chance the part will refreeze before you reach care, it is better to leave it frozen and get to a hospital than to thaw and refreeze it.
Keeping pipes from freezing
| Where | What to do |
|---|---|
| Exposed pipes in unheated space | Foam sleeve insulation, or heat tape rated for the pipe and installed to its instructions |
| Pipes in exterior walls | Open sink base cabinet doors so room air reaches them; move chemicals out of reach of children first |
| Faucet farthest from the meter | Let it drip during a hard freeze — moving water and the relieved pressure both help |
| Outdoor spigots | Disconnect hoses in fall; drain and shut the interior valve if there is one |
| Whole house, if leaving | Leave heat on at a low setting rather than off; better still, shut the main and drain the lines |
| Crawlspace and garage | Close vents and doors; a poorly insulated crawlspace is where most burst pipes start |
A dripping faucet costs a trivial amount of water against a repair bill that starts in the hundreds and climbs fast once drywall and flooring are involved. If the cold is exposing how thin the envelope is, the insulation calculator and the heating cost savings calculator are the off-season version of this conversation.
Thawing a pipe without starting a fire
If a faucet gives you nothing on a freezing morning, leave that faucet open so meltwater has somewhere to go and pressure can escape. Then warm the pipe from the faucet end back toward the frozen section, using a hair dryer, warm towels wrapped around it, or a space heater kept a safe distance from anything flammable. Work slowly.
Do not use a blowtorch, a propane torch, a charcoal heater or any open flame. Thawing pipes with a torch is a well-documented cause of house fires, and it also damages the pipe. If you cannot find the frozen section, if the pipe has already split, or if you smell anything wrong, shut off the main water valve and call a plumber. Everybody in the house should know where that valve is before they need it.
Heat, light and a plan for the outage
Space heaters need three feet of clearance from anything that burns, a wall outlet rather than an extension cord or power strip, and a person awake in the house. Fireplaces and wood stoves need a working flue and a screen. Candles are the wrong answer during an outage; battery lanterns are cheap and do not tip over.
The rest is unglamorous: charge phones and battery packs before the storm, fill bottles with water in case a pump loses power, know that a full freezer holds temperature far longer than a half-empty one, and keep the car above a quarter tank so it can serve as a place to warm up — outdoors, engine running only with a clear exhaust pipe and never in a garage. If someone in the house depends on powered medical equipment, that is the plan you build first and everything else follows it.
Questions people ask
Can I run a generator in the garage if the door is open?
No. An attached garage with the door open still accumulates carbon monoxide to lethal levels, and it shares air with the house. A generator belongs outdoors, well away from the building, and far from any window, door, vent or air intake, with the exhaust directed away from the structure. The same rule covers charcoal grills, gas grills, camp stoves and any propane heater not specifically rated for indoor use. Because carbon monoxide has no smell or color, a CO alarm on every level of the home is what actually detects it.
What is the simplest way to stop pipes from freezing?
Let the faucet farthest from where water enters the house drip during a hard freeze, and open the cabinet doors under sinks on exterior walls so heated room air reaches the plumbing. Beyond that, insulate any pipe running through an unheated crawlspace, garage or attic, disconnect garden hoses in the fall, and if you leave for a trip, leave the heat on at a low setting instead of turning it off. Draining the system and shutting the main is the thorough version for a long absence.
How do I thaw a frozen pipe safely?
Open the affected faucet first so melting water and pressure have an escape, then warm the pipe gradually from the faucet end back toward the blockage using a hair dryer, warm wet towels or a space heater set well away from anything flammable. Never use a blowtorch or any open flame — this is a recognized cause of house fires and it damages the pipe. If you cannot locate the frozen section or the pipe has already split, shut off the main water valve and call a plumber.
What are the first signs of hypothermia?
Hard shivering, clumsiness with the hands, stumbling and slurred or confused speech. The dangerous turn is when the shivering stops and the person becomes quiet, drowsy and cooperative, which reads as improvement and is not. Call 911, get them into shelter, take off wet clothing, and wrap them in dry blankets, warming the chest and trunk rather than rubbing the arms and legs. Do not give alcohol and do not put them straight into hot water.