How to keep your home cooler without air conditioning

Keep heat out early, and have a cooler place to go before your home becomes unsafe.

The answer in 2 lines. Close sun-facing blinds or curtains before rooms heat up. Open windows when outdoor air is cooler and air quality is acceptable; close them when hot air would enter. Reduce cooking and other indoor heat sources. A fan moves air rather than cooling the room, and CDC guidance, checked in 2026, recommends using fans only when the indoor temperature is below 90°F. If your home stays hot, spend time in an air-conditioned public building or cooling center. Do not wait for someone to become ill before leaving.

The first steps

Block direct sunlight. Close curtains, shades or blinds on exposed windows before the sun heats the room.
Compare indoor and outdoor conditions. Open windows only when cooler outdoor air can help and smoke, pollution, weather and security allow.
Choose a backup destination. Identify an air-conditioned place and a way to get there, especially if anyone has health conditions or limited mobility.

Stop: danger

Possible heat stroke: confusion, slurred speech, collapse or loss of consciousness in the heat means call 911. Skin may be dry or sweaty. Move the person somewhere cooler and cool them with wet cloths while help comes. Do not give fluids. See the National Weather Service first-aid guidance for symptoms and actions.
Heat exhaustion: heavy sweating, weakness, dizziness, headache or nausea calls for stopping activity and moving somewhere cool. Offer sips of water if the person is alert and able to swallow. Seek medical help for vomiting, worsening symptoms or failure to improve.

What helps inside the home

Shade: use existing window coverings during sunny hours. Exterior shading can reduce sunlight before it reaches the glass.
Cooler outdoor air: create cross-ventilation when conditions allow, then close windows as outside temperatures rise. Hot, humid nights may offer little relief.
Fans: use them for comfort only under suitable conditions. CDC guidance, checked in 2026, says to use fans only when the indoor temperature is below 90°F. Feeling a breeze does not prove the room is safe.
Less added heat: avoid using the oven, dryer and other heat-producing equipment during the hottest part of the day. Switch off unnecessary lights and electronics.

Read the Department of Energy explanation of natural ventilation to understand when outdoor air can help. It specifically warns against natural ventilation when outdoor air quality is poor.

What not to do

Keeping windows open simply because it is nighttime when outside air remains hotter or smoke is present.
Relying on a fan alone in a dangerously hot room.
Waiting for thirst or severe symptoms before taking heat precautions.
Leaving children or pets in a parked vehicle while looking for a cool place.

Cool the person as well as the room

Wear light clothing, reduce strenuous activity and use a cool shower or damp cloths for relief. Drink water regularly. If a clinician has limited your fluids, ask how to manage hot weather rather than changing that plan yourself.

Check on older relatives, people living alone, infants and anyone with chronic illness. Pregnancy and some medicines can increase heat-related risks. Ask a clinician or pharmacist about your situation; do not stop or change medication on your own.

Use the CDC heat-health guidance to review hydration, symptoms, medication planning and household precautions. Make arrangements for help reaching a cool location before conditions deteriorate.

Check local risk and find relief

Enter your ZIP code in the CDC HeatRisk dashboard to review the local forecast and recommended precautions. Check its air-quality information before using outdoor air to cool your home.

In New York City, call 311 or see the NYC cooling center fact sheet (2026) to find a location, and confirm current opening hours before traveling. Elsewhere, check your city or county website. Cooling-center availability varies by community and event.

Elsewhere, the CDC's Stay Cool section explains how to seek an air-conditioned location, including through local assistance. Confirm transportation, accessibility and pet arrangements. An air-conditioned library or recreation building may help while open; arrange another option for a hot night.

Good to know

These measures can reduce heat buildup, but they cannot guarantee a safe indoor temperature during extreme heat.
The EPA's heat and indoor-air guidance explains fan limitations and why access to air conditioning matters. Use it to prepare a household backup plan.
There is no single nationwide temperature reduction to promise from curtains, ventilation or shading: the building, climate and outdoor conditions change the result.

Illustrative example: In Baltimore, Denise closes her sunny-side blinds and postpones baking. The outdoor air remains hot and humid after sunset, so opening windows brings little relief. She checks the local heat forecast and arranges to stay with a relative who has air conditioning. She also calls an older neighbor to make sure they have somewhere cool to go.

A made-up story, for illustration.

Bobby

Sources, verification, confidence

Verified on November 5, 2026, for the United States. Confidence: high for heat precautions, emergency symptoms and the CDC's fan guidance, checked in 2026; medium for cooling-center availability, which must be checked locally. No fixed temperature reduction is promised.