When Shakira Franklin drives from West Baltimore to her job near the city's Inner Harbor, she can feel the summer heat ease up like a fist loosening its grip.
"I can actually feel me riding out of the heat. When I get to a certain place when I'm on my way, I'll turn off my air and I'll roll my windows down," says Franklin. "It just seems like the sun is beaming down on this neighborhood."
Franklin isn't imagining that. Her neighborhood, Franklin Square, is hotter than about two-thirds of the other neighborhoods in Baltimore — about 6 degrees hotter than the city's coolest neighborhood. It's also in one of the city's poorest communities, with more than one-third of residents living in poverty.
Across Baltimore, the hottest areas tend to be the poorest and that pattern is not unusual. In dozens of major U.S. cities, low-income neighborhoods are more likely to be hotter than their wealthier counterparts, according to a joint investigation by NPR and the University of Maryland's Howard Center for Investigative Journalism.
Those exposed to that extra heat are often a city's most vulnerable: the poorest and, our data show, disproportionately people of color. And living day after day in an environment that's literally hotter isn't just uncomfortable, it can have dire and sometimes deadly health consequences — a fact we found reflected in Baltimore's soaring rates of emergency calls when the heat index spiked to dangerous levels.
According to a Howard Center analysis of U.S. census data and air temperature data obtained from Portland State University and the Science Museum of Virginia, the hottest neighborhoods in Baltimore can differ by as much as 10 degrees from the coolest.
And Baltimore is not an extreme case. NPR analyzed 97 of the most populous U.S. cities using the median household income from U.S. Census Bureau data and thermal satellite images from NASA and the U.S. Geological Survey. In more than three-quarters of those cities, we found that where it's hotter, it also tends to be poorer. And at least 69 had an even stronger relationship than Baltimore, the first city we mapped.
This means that as the planet warms, the urban poor in dozens of large U.S. cities will actually experience more heat than the wealthy, simply by virtue of where they live. And not only will more people get sick from rising temperatures in the future, we found they likely already are.
"Before I knew it, I was gasping for air"
In the summer of 2018 in Baltimore, when the heat index reached 103 degrees — the threshold deemed dangerous by the National Weather Service — EMS calls increased dramatically citywide for potentially fatal heat stroke. But calls increased for chronic conditions too: EMS calls for chronic obstructive pulmonary disorder (COPD) increased by nearly 70%. Calls for respiratory distress increased by 20%. Calls for cardiac arrest rose by 80%. And those for high blood pressure more than doubled. Other conditions also spiked: psychiatric disorders, substance abuse, and dehydration, among others.
The heat affected residents citywide, but even when controlling for income by looking only at the patterns of Medicaid patients, there were differences across the city. From 2013 to 2018, Medicaid patients in Baltimore's hottest areas visited the hospital at higher rates than Medicaid patients in the city's coolest areas. The low-income patients in the city's hot spots visited more often with several conditions, including asthma, COPD and heart disease, according to hospital inpatient and emergency room admissions data from Maryland's Health Services Cost Review Commission.
In the Franklin Square neighborhood of West Baltimore, Shakira Franklin knows the link between heat and health all too well. She says her asthma is triggered by heat.
On a Saturday in July, Franklin says she was making the same drive she often makes from her home to the city's harbor. A heat wave was gripping the city, with temperatures reaching 100 degrees and above. Franklin says she normally tries to stay inside on days like that, but she had to get to work. That's when she had her first asthma attack in nearly five years.
"Before I knew it, I was gasping for air. It doesn't even take me 10 minutes to get from home to my other job. Just like that," says Franklin, who says an attack feels like drinking water through a pinched straw.
"Your windpipe is that straw and that water is the breaths you can take," Franklin says. "You're trying to bring your air through as much as you can."
Doctors in emergency departments near Baltimore's hotter neighborhoods say they prepare each summer for an increase in heat-related conditions.
"A lot of times the heat played a factor in making a chronic condition acutely worse," says Dr. Amit Chandra, chief of emergency medicine at the University of Maryland Medical Center Midtown Campus. He says that's especially true for cardiovascular conditions.
"The worse your circulatory system is, the worse you are at getting cool," says Chandra, who is also a faculty member at the University of Maryland School of Medicine. A weak or damaged heart might struggle to pump extra blood to the skin so heat can radiate off the body. Even sweating, which also gets rid of heat by evaporation, can put stress on the heart.
Respiratory conditions can become aggravated too, in part, because heat can actually worsen air quality and because conditions like asthma and COPD can be triggered by high heat and humidity.
Chandra says even looking at patients' medical records wouldn't necessarily tell the full story of how heat could be harming their health.
"We wouldn't diagnose them at the end of the day with heat exhaustion or heat stroke necessarily unless their temperature went up," Chandra says. "So there's probably quite a few folks that are affected by the heat, and we're not really tracking or measuring."
Regardless of where they live, people in poverty are more vulnerable to many chronic conditions, including some made worse by heat, like asthma and heart disease.
"Our patients are plagued by poverty, substance abuse and unfortunately some of the patients don't have great access to health care," says Dr. Reginald Brown, chair of emergency medicine at Bon Secours Hospital Baltimore in West Baltimore and a faculty member at the University of Maryland School of Medicine.
"As far as the impact [of heat] to our patients, it's just another thing that complicates their lives," he added.
The urban heat island
Cities in general tend to be hotter than their natural surroundings, thanks to a phenomenon known as the urban heat island.
"If you have less green cover, you will almost always have higher temperatures, and greater exposure to heat," says Brian Stone, director of the urban climate lab at the Georgia Institute of Technology.
Trees provide shade, but they also cool the environment down through the evaporation of water from their leaves — a process similar to how humans sweat to cool down.
"When you pave over an area, particularly if it had green plants, you have interrupted that cycle," Stone says. "Not only have you sealed the surface, you have put a lid on it, so evaporation cannot happen."
Pavement — particularly if it's black — absorbs heat and holds it in. At night, a city of more than 1 million people can be as much as 22 degrees warmer than its surroundings. Even the buildings themselves, Stone says, can create a sort of canyon that traps heat.
Given these elements, Stone says it makes sense that many low-income areas are hotter than richer areas.
"Lower-income parts of the city tend to have less green cover," Stone says. "That's something that we see across a lot of cities."
The pattern of who lives closer to those sources of heat is not just a matter of poor versus rich, it is also often a matter of black and brown versus white. Nationwide, many of the low-income communities NPR found to be hotter — often with fewer trees, more concrete and closer to highways and factories — are also communities of color.
"It wasn't just a coincidence that communities of color end up in some of the most undesirable places," says Miya Yoshitani, executive director of the Asian Pacific Environmental Network, which focuses on environmental justice issues affecting working-class Asian and Pacific Islander immigrant and refugee communities.
Yoshitani explains that policies like redlining — a practice, beginning in the 1930s and banned by the Fair Housing Act in 1968, in which neighborhoods were marked high risk for mortgage lenders in large part based on their racial makeup — forced people of color into less desirable areas. In Baltimore, the city's hottest neighborhoods, many of which are predominantly African American, still line up fairly consistently with the neighborhoods marked "hazardous" on a 1937 map created by the Home Owners' Loan Corp.
"People of color, African American communities, indigenous communities in the beginning and then immigrant communities as they came to the United States were not given a choice about where they could live, where they could raise their families, where they could work," Yoshitani says. "Those choices were made for them and that legacy continues today."
"They can't escape it"
In the majority of the cities NPR mapped, poverty was linked to heat, adding a second layer of risk to an already at-risk population. This is not only because poverty itself is a health hazard, but because poverty is also tied to other factors that can make it harder to get cool.
"People with money, of course, can do that a lot better than people with less money," says Dr. Georges Benjamin, executive director of the American Public Health Association.
He says no one is immune to climate change, but wealthier people can more easily control their exposure to heat by using air conditioning — which on its own contributes to climate change — or even by moving to a cooler part of the city.
"On the other hand, the folks with less money, they're going to be in their one home. And they're going to have to deal with the conditions in their one home," Benjamin says. "If they're going to be in an area where it's real hot, they're going to have to find other ways to adapt, but they can't escape it."
The urban poor, already often in hotter environments and already at higher risk for health problems, will have a harder time escaping climate change.
"It is the most significant public health problem that we have. It's going to be here for a long time. And it's getting worse," Benjamin says.
"This is ours"
There are strategies to cool down a city: investing in public transit, designing roofs that reflect sunlight, and planting more trees, among others.
In Baltimore, the city is working to combat urban heat. The government has installed cool roofs, turned vacant lots into community green space and strategically planted and maintained trees in low-income neighborhoods, among other initiatives. But the city's own arborist told the Howard Center that Baltimore is not on track to meet its goal of increasing the tree canopy to 40% by 2037.
"We're doing a lot with a little," says Anne Draddy, the city's sustainability coordinator.
The neighborhood where Shakira Franklin lives has increased its tree canopy over time. But by 2015, it still was among the city's lowest. Franklin says she's not optimistic the city will be able to cool down her neighborhood anytime soon.
"The city has a lot of responsibility. And I think that we would be close to the bottom of the list to be honest," she says.
There's a grassy vacant lot near her apartment where Franklin often takes a break from her job as a landscaping crew supervisor at Bon Secours Community Works, a nearby community organization owned by Bon Secours Health System.
It's one of the few places in the neighborhood with a lot of shade — mainly from a large tree Franklin calls the mother shade. She helped come up with the idea to build a free splash park in the lot for residents to cool down in the heat. Now Bon Secours is taking on the project.
"This was me taking my stand," Franklin says. "I didn't sit around and wait for everybody to say, 'Well, who's going to redo the park?' "
Daniel Greenspan, an architectural fellow working on the project, says they're about halfway to their current fundraising goal — with plans to buy the lot from the city.
On a hot Saturday this summer, Bon Secours and the neighborhood's community association threw a party in the lot. Children ran through streams of water from a pop-up fountain, while adults discussed and voted on potential designs for the new park.
"Our kids, they deserve it," says Franklin, who has two children. "I just feel like it's a long time coming to just have something to say that we built this here for us. This is ours."
Franklin says the park would become a refuge for people who can't escape the heat — and it will indeed be a place to cool off in this neighborhood. But worldwide, heat waves are getting hotter and more frequent, and the past five years have been the hottest ever recorded.
To determine the link between heat and income in U.S. cities, NPR used NASA/U.S. Geological Survey satellite imagery and U.S. Census American Community Survey data. An open-source computer program developed by NPR downloaded median household income data for census tracts in the 100 most populated American cities, as well as geographic boundaries for census tracts. NPR combined these data with TIGER/Line shapefiles of the cities.
The software also downloaded thermal imagery for each city from NASA's Landsat 8 satellite, looking for days since 2011 in June, July and August when there was less than 4% cloud cover. NPR reviewed each of the satellite images and removed images that contained clouds or other obscuring features over the city of interest. In cases when there were multiple clear images of a city, we used the thermal reading that showed a greater contrast between the warm and cool parts of the area of interest. In cases where there were no acceptable images, we manually searched for additional satellite images and found acceptable images from Landsat 8 for every city except for Hialeah and Miami, Fla., and Honolulu, which are frequently covered by clouds.
For each city, NPR aligned the satellite surface temperature data with the census tracts. For each census tract, the software trimmed the geography to only what is contained within the city of interest's boundaries, then removed any lakes, rivers, ocean, etc. It calculated a median temperature reading for each census tract. When all of the tracts in a city were completed, it calculated a correlation coefficient (R) of the tracts to find the relationship between income and heat.
The satellite data measure temperature at a surface, such as the ground or a rooftop. We used this measurement rather than ambient temperature, which measures the air about 2 meters above the ground. Measuring air is a more accurate measure of how people experience heat, but satellite data are more widely available than air temperature data. Using that data allowed us to provide a more complete snapshot of temperature trends across many cities.
To determine the relationship between heat and poverty in Baltimore, the Howard Center for Investigative Journalism used block-by-block temperature data showing variations in Baltimore's urban heat island captured by researchers at Portland State University and the Science Museum of Virginia on Aug. 29, 2018. For each "community statistical area" in Baltimore, the Howard Center computed a median temperature and joined it to a U.S. Census American Community Survey data set with the poverty rate for each area and then calculated the correlation coefficient (R).
ARI SHAPIRO, HOST:
In big cities across the U.S., low-income neighborhoods are hotter than wealthier ones. That's the finding of a joint investigation by NPR and the Howard Center for Investigative Journalism at the University of Maryland. As NPR's Meg Anderson reports, that heat can be deadly.
MEG ANDERSON, BYLINE: In a vacant lot in her West Baltimore neighborhood, Shakira Franklin is describing the first asthma attack she's had in nearly five years. It happened a few days earlier when temperatures hit 100 degrees.
SHAKIRA FRANKLIN: In this neighborhood, that feels like 110.
ANDERSON: For Franklin, that's a big deal. Her asthma is triggered by heat.
FRANKLIN: You know, I didn't really come outside, but I had to go to work. And before I know it, I was gasping for air.
ANDERSON: Breathing felt like trying to drink water through a pinched straw.
FRANKLIN: You're gasping at this point. You're trying to bring your air through as much as you can.
ANDERSON: She says when she drives out of her neighborhood to her job by the city's harbor, she can actually feel the breeze get cooler.
FRANKLIN: Like, I can actually feel me riding out of heat. Like, when I get to a certain place when I'm on my way, I'll turn off my air, and I'll roll my windows down to save gas.
ANDERSON: And so people know that.
FRANKLIN: Yeah. When you from this area, yeah, you know it.
ANDERSON: Franklin isn't imagining that change in temperature. Her neighborhood, Franklin Square - no relation to her name - is hotter than about two-thirds of the neighborhoods in Baltimore. It's also in one of the city's poorer areas. That's according to an analysis by NPR and the Howard Center.
Citywide in Baltimore, the hottest neighborhoods can differ by as much as 10 degrees from the coolest, and the hottest parts of the city also have higher rates of poverty. We wanted to see just how common that pattern is across the country. We mapped 97 major U.S. cities by heat and income. The vast majority have that same pattern, to varying degrees. And more than two-thirds had an even stronger link between heat and income than Baltimore did. That matters because heat can have potentially fatal consequences. And, our analysis shows, the people exposed to that extra heat in the hottest parts of town are often the city's poorest and disproportionately people of color. On top of that, cities already tend to be hotter than their rural surroundings.
BRIAN STONE: If you have less green cover, you will almost always have higher temperatures and greater exposures to heat.
ANDERSON: Brian Stone, director of the Urban Climate Lab at the Georgia Institute of Technology, says trees and green space cool the air and provide shade. Pavement, on the other hand, absorbs heat and holds it in. At night, a large city can be as much as 22 degrees warmer than its surroundings. Plus, common features of cities, like major roadways, create even more heat.
STONE: So all of the pollution that comes out of the tailpipe of our vehicles - there's also a lot of waste heat.
ANDERSON: Stone says it makes sense that low-income neighborhoods often suffer more because compared to wealthier areas, they tend to have even fewer trees, even more concrete and even more waste heat from nearby factories or highways. That means as the planet warms, the urban poor will actually experience more heat simply by virtue of where they live.
We went to the places in Baltimore where our data said it was the hottest, and residents there described oppressive summer heat.
LEE LEWIS: It's like the sun just comes in and sit right here.
HANNAH TRENT: It was so hot that you could smell the heat.
JOE BOSTON: When it's hot like it is now, most of the time, I stay in.
IANTHIA DARDEN: I can feel the wheezing coming and I need to go someplace where I know I need to get cool.
ANDERSON: That was Ianthia Darden, Joe Boston, Hannah Trent and Lee Lewis.
Living day after day in the heat isn't just uncomfortable; it can be deadly. The Howard Center obtained EMS and hospital data in Baltimore and compared it to the city's heat patterns. When the heat index reached dangerous levels last summer, EMS calls increased citywide for heat stroke. But calls also increased for chronic conditions, including several cardiovascular and respiratory conditions.
And even when controlling for income, there were differences across the city. From 2013 to 2018, Medicaid patients in Baltimore's hottest areas visited the hospital with those conditions at higher rates than Medicaid patients in the cooler areas, according to the Howard Center analysis.
AMIT CHANDRA: A lot of times, the heat played a factor in making a chronic condition acutely worse.
ANDERSON: Dr. Amit Chandra runs the emergency room at an inner-city University of Maryland hospital. He says that's especially true for heart conditions because the body has to work harder to cool off. Respiratory conditions can increase, too, because heat can actually worsen air quality. Chandra says even looking at a patient's medical records won't necessarily tell you how heat could be harming their health.
CHANDRA: We wouldn't diagnose them at the end of the day with heat exhaustion or heat stroke, necessarily, unless their temperature went up. So there's probably quite a few folks that are affected by the heat, and we're not really tracking or measuring.
ANDERSON: In the ER at Bon Secours Hospital in West Baltimore, James Batson is wheezing and unable to catch his breath.
REGINALD BROWN: How you feeling, sir?
ANDERSON: The heat index, which factors in humidity, is nearly 90 degrees.
BROWN: Mind if I take another listen to your...
JAMES BATSON: Yeah.
BROWN: ...To your chest here?
ANDERSON: Dr. Reginald Brown examines him.
BROWN: Deep breath.
ANDERSON: Batson has asthma and chronic obstructive pulmonary disorder, or COPD. He's wearing an oxygen mask over his nose and mouth.
Do you feel like your asthma and COPD gets worse in the summertime?
BATSON: Only when the humidity's high.
ANDERSON: What does that feel like?
BATSON: It just - you can't breathe. Just feel like it - chest going to bust open.
ANDERSON: He says when it's humid, he can't breathe, and it feels like his chest is going to bust open.
Most patients who come to Bon Secours Hospital are low-income, and many are underinsured. People in poverty are more vulnerable to many chronic conditions, including some that are made worse by heat. And having less money can make it harder to cool off in the first place. Air conditioning, for instance, might be a pricey luxury for a family struggling to buy groceries.
GEORGES BENJAMIN: People with money, of course, can do that a lot better than people with less money.
ANDERSON: Dr. Georges Benjamin is executive director of the American public health association.
BENJAMIN: Folks with less money - they're going to be in their one home, and they're going to have to deal with the conditions in their one home. And if they're going to be in an area where it's real hot, they're going to have to find other ways to adapt, but they can't escape it.
ANDERSON: The urban poor, already often in hotter environments and already at higher risk for health problems, will have a harder time escaping climate change.
BENJAMIN: It is the most significant public health problem that we have. It's going to be here for a long time, and it's getting worse.
ANDERSON: There are ways to cool down a city - investing in public transit, designing roofs that reflect sunlight, planting trees. In Baltimore, city officials are working on planting trees in the city's low-income neighborhoods. The neighborhood where Shakira Franklin lives has increased its tree canopy over time, but in recent years, it's still been among the city's lowest.
FRANKLIN: The city has a lot of responsibility, and I think that we would be close to the bottom of the list, to be honest.
ANDERSON: So she's not waiting. Franklin and the organization where she works as a landscaping crew supervisor are planning to build a splash park in a lot near her house.
FRANKLIN: Our kids - they deserve it. And I just feel like it's a long time coming to just have something to say that we built this here for us. This is ours.
ANDERSON: On a hot Saturday this summer, they threw a party there, complete with a pop-up water fountain for kids to cool off.
UNIDENTIFIED CHILD: Look what I can do.
ANDERSON: But worldwide heat waves are getting hotter and more frequent, and the last five years have been the hottest ever recorded.
Meg Anderson, NPR News.
SHAPIRO: You can see the 97 U.S. cities NPR mapped as part of our investigation into heat, health and income at npr.org. And our City Heat series continues tomorrow with a look at why one of the best ways to combat urban heat is also one of the most challenging to maintain - tree cover. Transcript provided by NPR, Copyright NPR.