Staying warm and cool without power

01 — Passive heating strategy

A home loses heat faster from more rooms. Consolidating into one well-insulated interior space dramatically extends how long warmth lasts.

The most effective passive heating strategy is to reduce the volume of space you need to keep warm. Consolidate everyone into a single interior room — ideally one with the fewest exterior walls and smallest window area, on an upper floor where heat naturally rises from the rest of the structure. Close the doors to all other rooms to prevent heat from dispersing through the full house.

• Hang blankets over windows and exterior-facing doors to reduce radiant heat loss. Even interior doorways benefit from blanket curtains when you're containing heat to one room.
• Use towels or draft stoppers at the base of doors. Cold air infiltration from gaps under exterior doors is a significant heat loss source.
• In daytime with sunny conditions, let sunlight in through south-facing windows — solar gain provides measurable passive heat. Close curtains at sunset to retain that heat.
• Sleeping bags are more efficient than blankets for retaining body heat — a quality sleeping bag rated to 0°F will keep an adult warm in temperatures well below freezing without any external heat source.
• Body heat is the last line of defense: multiple people in a small space significantly raise the ambient temperature.

02 — Clothing layers

The correct layering system traps warm air against the body and moves moisture away from skin — in that order.

Heat loss accelerates dramatically when skin or clothing is wet. Wet cotton is especially dangerous in cold environments because it holds moisture against the skin and conducts heat away from the body rapidly. The layering system works by pairing materials that each do one specific job.

1. 1

   Base layer: moisture-wicking

   Merino wool or synthetic (polyester) next to skin. Moves sweat away from body. Not cotton — cotton absorbs and holds moisture.

2. 2

   Insulating layer: heat retention

   Fleece, down, or wool. Traps warm air in small pockets. Multiple thin insulating layers are more effective and adjustable than a single thick layer.

3. 3

   Outer layer: wind and moisture block

   Windproof and water-resistant shell. Prevents cold air from penetrating and displacing the warm air in the insulating layer. Less necessary indoors, critical for any time outdoors.

Do not neglect extremities: 30 to 40 percent of body heat is lost through the head. A hat is one of the highest-impact items for warmth retention indoors when heating fails. Hands and feet also lose heat rapidly — warm socks and gloves or mittens matter even indoors at 40°F.

03 — Cooling without power

The most effective cooling strategies work by moving heat away from the body, not by cooling the air.

In a power outage during hot weather, the goal is to prevent heat-related illness — particularly for older adults, young children, and people with chronic conditions who are at higher risk of heat stroke.

• Move to the lowest floor or basement. Cool air is denser and sinks; the lowest floor of a home is typically the coolest during a hot day.
• Wet skin and use air movement. Evaporative cooling is extremely effective. Wet a cloth and apply to pulse points (wrists, neck, forehead). Any air movement — a battery-powered fan — dramatically accelerates evaporative cooling.
• Avoid outdoor activity during peak heat hours (typically 10 a.m. to 4 p.m.). If outdoors is necessary, work in the early morning.
• Cross-ventilate at night. When outdoor temperature drops below indoor temperature (typically after sunset), open windows on opposite sides of the house to create a cross-breeze that flushes hot air out and brings cooler air in.
• Use public cooling centers. Libraries, community centers, and malls are often open during heat emergencies as cooling centers. This is not a sign of failure — it is appropriate use of community resources during a health emergency.
• Recognize heat stroke signs: confusion, absence of sweating in extreme heat, very high body temperature. This is a medical emergency requiring immediate 911 call.

04 — Protecting pipes during a heating outage

Water freezes at 32°F. Pipes in exterior walls and unheated spaces begin to freeze before that, and can burst — flooding the house when they thaw.

During a prolonged winter heating outage, pipe protection is a secondary emergency that can turn a power outage into a serious structural event. Pipes in exterior walls, under sinks on exterior walls, in unheated crawl spaces, and in garages are most vulnerable.

• Let faucets drip slowly — both hot and cold, for fixtures on exterior walls. Moving water requires more energy to freeze than standing water.
• Open cabinet doors under sinks on exterior walls to allow warmer interior air to circulate around the pipes.
• If outage is prolonged and indoor temperature is dropping toward freezing, consider shutting off the main water supply and draining the pipes — this is the most reliable protection. Open all faucets after shutting off the main to drain remaining water. When power is restored and the house is warm, turn the main back on slowly and check for leaks.
• Know where your main water shutoff is before an emergency. It is typically in the basement, crawlspace, or outside near the foundation. If a pipe bursts, the first action is to turn off this valve.