When the power goes out during a deep freeze, your first job is keeping your body warm enough and your food safe, not fixing the grid. That means layering up, closing off unused rooms, watching everyone in the house for signs of hypothermia, and never using an outdoor heat source — like a generator or a grill — indoors. This guide walks through the warning signs, a before-the-storm checklist, and which heating methods are safe and which ones can kill you faster than the cold.
Warning Signs to Watch For First
Hypothermia is a medical emergency. In adults, warning signs include shivering, exhaustion, confusion, fumbling hands, memory loss, slurred speech, and drowsiness. In babies, watch for bright red, cold skin and very low energy. If someone’s temperature drops below 95°F, get medical attention immediately.
A person with severe hypothermia may look unconscious and may not seem to have a pulse or be breathing. Handle them gently, call for emergency help right away, and begin CPR if you’re trained to do so. Some hypothermia victims who appeared dead have been successfully resuscitated with prompt care.
Why Cold Becomes Dangerous Faster Than People Expect
Hypothermia happens when your body loses heat faster than it can make more. Once your body’s stored energy runs low, your core temperature drops, and a low core temperature affects the brain — which is part of what makes hypothermia so dangerous. A confused or drowsy person may not realize what’s happening to them and may not act to warm up.
This isn’t only a sub-freezing problem. Hypothermia can occur even at cool temperatures above 40°F if a person gets chilled from rain, sweat, or cold water. A power outage that leaves someone in damp clothes in a 45°F house overnight is a real risk, not just a deep-freeze one.
Who Faces Higher Risk
Some people need extra caution during a cold-weather outage:
- Older adults with inadequate food, clothing, or heating
- Babies sleeping in cold bedrooms
- Anyone outdoors for long periods, including people experiencing homelessness
- People who drink alcohol or use illicit drugs, which can mask the early warning signs
If someone in your household falls into one of these groups, check on them more often during an outage, not less.
Before the Outage: A Cold-Weather Power Checklist
- Have a battery-powered or hand-crank radio and flashlights with fresh batteries on hand
- Install a carbon monoxide detector and confirm it has a working battery
- Have your heating system checked by a qualified professional before winter, and have chimneys cleaned and inspected annually
- Keep extra blankets, warm layers, and a change of dry clothing accessible for everyone in the household
- Know where you’d go if you couldn’t heat your home safely — a community warming location matters more than trying to tough it out
- Plan ahead for anyone who depends on power for refrigerated medicine or an electric medical device
A stocked, checked emergency gear kit with flashlights, extra layers, and hand warmers makes the first hour of an outage far less chaotic.
Safe vs. Unsafe Indoor Heating During an Outage
- Portable generator: Never indoors. Run it outdoors only, away from windows, doors, and vents — it produces carbon monoxide, which is invisible and can be fatal indoors.
- Gas stove or oven: Never use for heat. It isn’t designed for space heating and creates a carbon monoxide and fire risk.
- Space heater: Safe with care. Plug it directly into an outlet, keep it at least 3 feet from anything flammable, and never leave it unattended.
- Fireplace or wood stove: Safe if the chimney has been inspected and there’s clearance from flammable items.
- Extra blankets and layered clothing: Always safe. No fire or carbon monoxide risk.
If a home battery or backup power system is part of your setup, confirm ahead of time what it’s actually rated to run — a unit that can’t carry a space heater is still useful for phones, radios, and medical devices.
Low-Cost Ways to Hold Heat In
You don’t need to buy anything to slow heat loss in a cold house:
- Close doors and vents to rooms you’re not using, and shut the basement door
- Place a rolled towel at the bottom of doors to block drafts
- Keep window coverings open in daytime sun and closed at night — a meaningful share of home heating loss happens through windows
- Seal obvious gaps around windows with weather stripping or caulk
What To Do If Someone Shows Signs of Hypothermia
- Get medical help as soon as possible
- Move the person into a warm room or shelter
- Remove any wet clothing
- Warm the center of the body — chest, neck, head, and groin — with an electric blanket if one is available, or skin-to-skin contact under dry layers
- Offer warm, non-alcoholic drinks if the person is conscious; never give anything to an unconscious person
- Once body temperature rises, keep the person dry and wrapped, including head and neck, and get them proper medical attention
Food Safety During the Same Outage
Keep freezers and refrigerators closed as much as possible. Throw away any food that has been above 40°F for two or more hours, or that has an unusual color, odor, or texture. For a fuller rundown on stretching supplies safely, see our emergency food and water guide.
FAQs
Can hypothermia happen indoors, not just outside?
Yes. A cold, powerless home — especially if someone is damp from sweat or spilled water — can bring on hypothermia even when the indoor temperature is above freezing.
Is it safe to run a generator in the garage with the door open?
No. Generators should only run outdoors, away from windows, doors, and vents, regardless of ventilation attempts inside an attached structure.
How cold does it have to be for hypothermia to set in?
There’s no single temperature cutoff. It can occur at temperatures above 40°F if a person is wet and becomes chilled, not only in extreme cold.
What’s the first thing to do if someone seems confused and is shivering during an outage?
Treat it as a possible sign of hypothermia: get them warm, dry, and into shelter, and seek medical attention — don’t wait to see if it passes on its own.
Evidence Limits and Educational Disclaimer
This article summarizes general public safety guidance from federal sources. It is educational information, not medical advice, and it cannot account for a specific person’s health conditions or a specific home’s heating setup. It does not diagnose, treat, or replace guidance from a qualified clinician or a licensed heating professional. See our full Medical Disclaimer for more detail. If you or someone with you is showing signs of hypothermia or frostbite, seek emergency medical care right away.