Scorching hot days tend to hit certain neighborhoods harder than others, a problem that becomes more dangerous during record-breaking heat like swathes of the US experienced over the past week. A new online dashboard shows how Latino neighborhoods are disproportionately affected in California.

“We want to provide facts, reliable data sources. We don’t want this to be something that gets erased from the policy sphere,” says Arturo Vargas Bustamante, faculty research director at the UCLA Latino Policy and Politics Institute (LPPI).

The Latino Climate & Health Dashboard includes data on extreme heat and air pollution, as well as asthma rates and other health conditions — issues that are linked to each other. High temperatures can speed up the chemical reactions that create smog. Chronic exposure to fine particle pollution, or soot, can increase the risk of a child developing asthma. Having asthma or another respiratory illness can then make someone more vulnerable to poor air quality and heat stress. Burning fossil fuels — whether in nearby factories, power plants, or internal combustion vehicles — makes all of these problems worse.

Latino neighborhoods have to cope with 23 more days of extreme heat a year compared to non-Latino white neighborhoods in California, the dashboard shows. LPPI defined extreme heat as days when temperatures climbed to 90 degrees Fahrenheit or higher.

If you’ve ever heard about a phenomenon called the urban heat island effect, big differences in temperature from neighborhood to neighborhood probably wouldn’t come as a surprise. Areas with less greenery and more dark, paved surfaces and waste heat from industrial facilities or vehicles generally tend to trap heat. Around 1 in 10 Americans lives in a place where the built environment makes it feel at least 8 degrees Fahrenheit hotter than it would without that urban sprawl according to one study of 65 cities from last year. And after years of redlining that bolstered segregation and disinvestment in certain neighborhoods in the US, neighborhoods with more residents of color are often hotter than others.

The dashboard includes fact sheets by county to show what factors might raise temperatures in certain areas. In Los Angeles County, for example, only four percent of land in majority-Latino neighborhoods is shaded by tree canopy compared to nine percent in non-Latino white neighborhoods. Conversely, impervious surfaces like asphalt and concrete that hold heat span 68 percent of land in Latino neighborhoods compared to 47 percent in majority non-Latino white areas in LA County.

For this dashboard, LPPI defines a Latino neighborhood as a census tract where more than 70 percent of residents identify as Latino. It used the same 70 percent threshold to define non-Latino white neighborhoods.

Latino neighborhoods in California are also exposed to twice as much air pollution and have twice as many asthma-related ER visits as non-latino white neighborhoods, according to the dashboard. It brings together data from the Census Bureau, US Centers for Disease Control and Prevention, the state’s environmental health screening tool called CalEnviroScreen, and other publicly-available sources.

Efforts to keep these kinds of studies going are just as vital, so that people don’t have to rely on outdated information that no longer reflects current conditions on the ground. And other researchers have launched new initiatives to document the Trump administration’s environmental rollbacks. The Environmental Defense Fund and other advocacy groups, for instance, launched a mapping tool in April that shows 500 facilities across the US that the Environmental Protection Agency has recently invited to apply for exemptions to air pollution limits.

UCLA’s dashboard adds to the patchwork of more locally-led research campaigns, although it can’t replace the breadth of data that federal agencies have historically collected. “Of course, we don’t have the resources that our federal government has,” Bustamante says. “But with what we are able to do, I think that one of the main aims is to keep this issue [at the top of] the agenda and provide reliable information that will be useful for community change.”

Data like this is a powerful tool for ending the kinds of disparities the dashboard exposes. It can inform efforts to plant trees where they’re needed most. Or it can show public health officials and community advocates where they need to check in with people to make sure they can find a safe place to cool down during the next heatwave.