I can't heat or cool my whole house. What do I do?
Do not start by trying to replace your entire HVAC system with backup power. Protect people first by creating a smaller warm or cool zone and using limited fuel or electricity where it does the most work.
Cold outage: create a warm room
Choose one useful room or zone. Favor a space that can be closed off, fits the household and sleeping gear, and has limited exterior exposure. A safe, maintained fireplace or wood stove can make a larger room the better choice.
Close open passages when practical. A tension rod with a heavy curtain, moving blanket or other temporary divider can reduce air exchange between the occupied zone and unused parts of the house. Never block a needed exit or place temporary barriers near flame or hot surfaces.
Use free heat and stop drafts. Let useful winter sun through sun-facing windows during the day, then cover windows as temperatures fall. Close drapes and use towels or rolled blankets at drafty door bottoms.
A tent can create a smaller sleeping microclimate
If the room becomes very cold, a normal camping tent pitched inside can create a much smaller space around sleeping people. Use sleeping bags, blankets and insulated pads. Do not obstruct ventilation, and never put a candle, combustion heater or other flame inside or against a tent.
Useful cold-outage equipment
Insulated doorway curtain or moving blankets: helps isolate the occupied zone.
Window insulation film: inexpensive draft and heat-loss reduction.
Sleeping bags and insulated pads: especially important against cold floors.
Low-watt heated blanket or throw: targeted warmth can require far less electricity than a 1,500W space heater.
Smoke and CO alarms: essential around permitted combustion heat.
Backup power: prioritize targeted warmth, communications and critical loads before trying to heat a large space electrically.
If you have a fireplace or fuel-burning heater
Use only equipment designed and installed for that purpose, follow its instructions and maintain working smoke and carbon-monoxide alarms. Never use an oven, grill, camp stove, generator or outdoor heater as improvised indoor heat.
Hot outage: stop heat before it enters
Block direct sun early. Close shades or other effective coverings on the hottest sun-facing windows before peak heat.
Use the coolest safe area. A shaded lower-floor room or basement may be a better daytime refuge. Move water, medications, pets and charging gear there.
Use cooler night air when it is actually cooler and outdoor air quality is safe. Strategic cross-ventilation can purge accumulated heat. Close the house and block sun again before outdoor temperatures climb.
Cool people directly. Airflow, damp cloths or cooling towels, appropriate clothing, hydration and reduced physical activity use very little stored electricity.
Fans are not air conditioners. They move air but do not lower room temperature. In dangerous heat, relocation to air conditioning can be the correct decision.
What about a DIY swamp cooler?
A fan blowing across ice or water can create localized cooling, but it is not a replacement for air conditioning. Evaporative cooling works best in dry climates and is much less effective in humid conditions. Ice may also be more valuable for food or medical needs.
Useful hot-outage equipment
Rechargeable or efficient USB/DC fans: useful airflow with relatively low power demand.
Solar-blocking window coverings: preventing heat gain is easier than removing it later.
Cooling towels and simple personal-cooling gear: inexpensive and low-energy.
Power station sized for fans: much easier to sustain than whole-room air conditioning.
Efficient window or portable AC plus correctly sized backup power: a higher-capability option when extreme heat is a recurring risk.
I have $0 to spend. What can I do?
Cold: close unused rooms, block drafts with towels, use curtains or blankets as safe temporary dividers, bring bedding together, wear layers and hats, use daytime sun, and use an indoor camping tent as a smaller sleeping space if needed.
Heat: block sun early, move to the coolest safe room, avoid adding heat with ovens or dryers, use fans you already own, cool skin safely, use cooler night air when appropriate, and know where you can go for reliable air conditioning.
Know when staying is no longer the safe plan
Preparedness is not a contest to see how long you can tolerate an unsafe house. A warm room or cool zone buys time and reduces energy demand. If conditions become dangerous, especially for children, older adults, people with medical vulnerabilities or pets, move to a safely heated or cooled location when possible.
Home outage essentials →Plan backup power →Sources and research approach
Reviewed September 2026. Practical preparedness techniques are checked against recognized safety guidance and independent consumer information. LivSolv does not claim personal testing unless explicitly stated.
Consumer Reports: Winter Power Outage
CDC: Winter Storm Safety