This month’s heat wave may have subsided, but experts say extreme heat is no longer an occasional occurrence. As temperatures continue to rise across the United States, health experts warn that extreme heat remains the nation’s deadliest weather-related hazard. Researchers also say its dangers are not felt equally.

Several reports over the last few years have found that Black communities and other communities of color are often exposed to higher temperatures and face greater health risks during periods of extreme heat. Experts say those disparities are rooted in decades of housing, infrastructure and environmental policies that continue to shape how neighborhoods experience rising temperatures.

The issue recently drew renewed attention in a Word in Black opinion essay examining how extreme heat disproportionately affects Black communities. While writer Willy Blackmore highlighted the human impact of rising temperatures, research from universities and environmental organizations has found that historic disinvestment and discriminatory housing policies continue to leave many Black neighborhoods more vulnerable during periods of extreme heat.

Why some neighborhoods are hotter than others

A 2024 study from the Yale School of the Environment found that communities of color experience more extremely hot days than predominantly white communities. Researchers pointed to factors including historic redlining, limited tree canopy and the urban heat island effect, a phenomenon in which neighborhoods with more pavement and buildings absorb and retain more heat than greener areas.

According to Moms Clean Air Force, many predominantly Black neighborhoods have fewer trees, more asphalt and aging infrastructure, causing temperatures to climb higher than in wealthier or predominantly white communities nearby. Those same neighborhoods often have fewer resources to adapt to extreme heat, making residents more vulnerable as summers grow hotter.

Heat is both a public health and economic issue

Extreme heat can overwhelm the body’s ability to regulate its temperature, increasing the risk of heat exhaustion and life-threatening heat stroke, according to NPR. Older adults, young children, people with chronic illnesses and those who work outdoors face some of the greatest risks.

But staying safe is not always as simple as going inside.

Many families live in older homes without efficient cooling systems or struggle to afford rising electricity costs during the hottest months of the year. Others work jobs that require spending hours outdoors, limiting their ability to avoid dangerous temperatures.

Experts say these challenges often overlap in communities that have historically experienced disinvestment, making extreme heat not only a climate issue but also an economic and public health concern.

So, what can be done?

As climate change contributes to longer and more frequent periods of extreme heat, researchers and advocates say reducing heat-related illness will require more than emergency cooling centers and weather alerts.

In its analysis, Moms Clean Air Force noted that long-term investments such as expanding tree canopy, improving housing, increasing access to green space and strengthening neighborhood infrastructure can help reduce heat exposure while improving public health. The organization also argues that addressing extreme heat means confronting the legacy of discriminatory policies, including redlining, that have left many Black communities with fewer resources to adapt.

Researchers at the Yale School of the Environment similarly found that the unequal burden of extreme heat reflects decades of housing and land-use decisions rather than differences in climate alone. As another hot summer unfolds, experts say understanding who is most affected and why will be critical to reducing heat-related illnesses in the years ahead.