Practical Steps Can Lower Indoor Temperatures During Summer Heat

Millions of people across the United States have been placed under extreme heat warnings in recent weeks. Forecasters have described some events as once-in-a-century heatwaves, with temperatures in parts of the Northeast reaching triple digits. The National Weather Service has urged people to stay indoors during peak heat, citing health risks for older adults, children, and those without air conditioning.

Closing blinds or curtains during the hottest part of the day blocks sunlight that enters through windows. Matt Plouffe, an engineering consultant at Efficiency Vermont, said summer sun delivers heat right through windows and that keeping shades closed can lower indoor temperatures.

Moving cooking and laundry tasks to later in the day also reduces heat generated by appliances inside the home.

Opening windows at night creates a cross-breeze as outdoor temperatures drop. Plouffe said residents should take advantage of cooler summer evenings and close windows again in the morning before heat builds. Fans provide relief when pointed directly at people or placed near windows to pull in cooler air, and ceiling fans should run counterclockwise in summer.

Replacing heavy fabrics with linen or cotton and removing rugs can reduce heat retention. Lenka Ilic, principal architect at Apartment Renovation NYC, said natural fibers breathe and feel cooler to the touch. Closing doors to unused rooms and using naturally cooler spaces such as basements on warm nights can further limit heat exposure.

Thermal blinds and external shading such as overhangs or awnings block sunlight before it reaches windows. Ilic said these features stop heat at the source and are more effective than indoor blinds. Lighter wall colors reflect heat, while stone, tile, or concrete surfaces absorb heat during the day and release it slowly at night.