Six simple ways to keep your house cool during heat waves

Extreme heat is not just uncomfortable. It can turn a home into a health risk, drive up electricity bills and strain the grid at the same time, especially for renters and low-income households that cannot easily upgrade insulation or install new cooling equipment. The most effective responses are often simple, cheap and immediate: keep sunlight out, limit the heat you add indoors, and use the thermostat, fans and weather tools with a clear eye on safety.

Start with the window, because that is where much of the heat enters

Window coverings are one of the fastest ways to slow heat gain during the day. The U.S. Department of Energy advises using coverings to block daytime heat, which matters most in rooms that face strong sun for hours at a time. For people in apartments or older homes, this is one of the few cooling moves that does not require a renovation.

That matters because heat waves, as the National Weather Service defines them, are periods of abnormally hot weather that generally last more than two days. They can happen with or without high humidity, and they can expose large numbers of people to hazardous heat. In practical terms, every hour of afternoon sun that stays outside is an hour less work for your cooling system, or less stress on the home if you do not have reliable air conditioning.

Use the building itself as a cooling tool

The biggest energy savings come from making the home harder to heat in the first place. The Department of Energy says combining proper insulation, energy-efficient windows and doors, daylighting, shading and ventilation can keep a home cool with minimal air conditioning. That is a long-term strategy, but it points to the most durable answer: homes that hold heat out do not have to burn as much power to stay livable.

That lesson matters in cities, where urban heat islands can make neighborhoods about 1 to 7 degrees Fahrenheit hotter during the day and 2 to 5 degrees hotter at night than surrounding areas. The U.S. Environmental Protection Agency says heat islands can account for 5 to 10 percent of summertime electricity demand, which pushes up air-conditioning costs and peak energy demand while also increasing air pollution, greenhouse gas emissions and heat-related illness and mortality. In the eastern United States, the gaps can be especially pronounced in humid urban areas, where the neighborhood itself becomes part of the problem.

Cut the heat you create inside your own kitchen

Cooking can raise indoor temperatures fast, especially in small apartments and homes without strong cooling. The Centers for Disease Control and Prevention advises using the stove and oven less during hot weather, a practical step that can keep heat from building up during the hottest part of the day. Cold meals, shorter cooking times and prep that does not require the oven all reduce the burden on a room that is already fighting the weather.

This is one of the most useful tactics for households trying to stretch a tight utility budget. Every source of heat you avoid inside the home lowers the amount of cooling you need later, which can help with both comfort and energy costs. In a prolonged heat wave, small choices such as postponing baking or using less stovetop time can make a noticeable difference by evening.

Use fans, cool showers and a smarter thermostat, but know their limits

Fans can help people feel more comfortable, but the CDC says they will not prevent heat-related illness when temperatures are really hot. That distinction matters for households that rely on fans as their main cooling tool. A fan moves air; it does not lower the actual temperature enough to protect someone who is already overheating.

The CDC also recommends cool showers or baths, which can help the body shed heat more directly. On the energy side, the Department of Energy says to set programmable thermostats as high as comfortable in summer and raise the setpoint when away from home. That simple adjustment can save energy without giving up basic safety, especially when paired with shade, window coverings and other low-cost steps that reduce the load on the system.

Protect the people who face the highest risk first

Extreme heat can cause heat-related illness and death, and the CDC says more than 700 people die from extreme heat every year in the United States. The highest-risk groups include older adults, young children and people with chronic medical conditions such as heart disease, asthma or other lung disease. Other vulnerable groups include people with disabilities, pregnant women, low-income communities, people who lack quality housing, and indoor and outdoor workers who cannot simply step away from the heat.

That is why heat planning is not just about comfort. It is about keeping a person who is isolated, medically fragile or housing-insecure from crossing the line from discomfort into emergency. A cool room, a few hours of relief and reliable access to hydration can matter more than any single appliance when temperatures keep climbing.

Use the new forecast tools and treat heat like a public-safety alert

The CDC and the National Oceanic and Atmospheric Administration launched the Heat and Health Initiative on April 22, 2024, including a seven-day HeatRisk forecast tool nationwide. That forecast can help you decide when to close blinds early, rearrange outdoor work, visit a cooling space or check on a neighbor before the hottest hours hit. The same guidance also stresses staying cool, staying hydrated and knowing the symptoms of heat illness.

That broader view is important because extreme heat also reaches beyond individual homes. The National Weather Service says it can affect transportation, utilities, clean water and agriculture, which means a heat wave can create cascading problems even before a single outage occurs. When the forecast turns dangerous, the most effective response is not one trick, but a layered plan: keep the sun out, keep heat from building indoors, use cooling tools wisely and pay closest attention to the people and places that heat punishes first.