Exploring what a hotter Los Angeles means for health

Curiosity has its own reason for existence, Albert Einstein says, and in my case that reason is personal. My old radio station, a few years back, ran out of desks for all of its reporters, and we were encouraged to work from home, where I have no central air. By early afternoon from June on, I’d be sweating in that home bureau, and I’d notice my thinking slow down and get foggy. I started planning way more interviews in sleek, air-conditioned buildings. I’m not even one of the people most vulnerable to heat in Los Angeles. But who is?

Record temperatures aren’t just threatening cracks in distant polar ice — they’re raising questions about how well California’s most vulnerable city dwellers are coping with urban heat impacts.

Sprawling communities across the Los Angeles Basin suffer something called the urban heat island effect. It’s up to 27 degrees hotter in LA than surrounding rural areas. Climate change compounds the problem: summers in the city have been getting hotter, faster, for almost half a century.

And if you’ve ever found yourself in Van Nuys on a sweaty September day, you won’t be surprised that inequities abound. Some are geographic: Scientists have characterized the Los Angeles basin as a heat archipelago, with hotspot-islands dotting the landscape where sea breezes don’t reach, where trees are lacking and concrete is plentiful. (Common sense tells me I’d rather be under a tree than under a Denny’s sign on Sherman Way when it’s 95 degrees out.)

These heat archipelagos are reflected in temperature studies. Woodland Hills has plenty to complain about; coastal Mar Vista, not so much. And these temperatures are on the rise. While climate models suggest that downtown Los Angeles will more than triple the amount of its 95 degree days, they also predict that the San Fernando Valley will see the needle climb that high 92 times in the year 2050 compared to a quarter century ago — and the valley already counted 54 extremely hot days annually in 1990.

The heat archipelago likely affects the health of city dwellers unequally, too. Urban heat worsens air in the LA basin. Higher daytime temperatures, higher nighttime temperatures, and higher air pollution levels associated with urban heat contribute to respiratory and cardiac difficulties, heat exhaustion, heat stroke, and cramps. With all of these conditions, some people are more at risk. The state’s Office of Environmental Health Hazard Assessment (OEHHA) has suggested that particularly vulnerable people are black, women, low-income, very old and very young.

While we expect health impacts to rise as temperatures do, we’re still learning a lot about tracking those impacts. Another OEHHA study found that more than half the time when people were hospitalized for heat-related symptoms, no weather service heat advisory was in place.

Even as California scientists and policymakers commit a lot of resources to studying our landscape, very little is known about how people live under that blanket of heat, every day.

One scientist I’ve spoken to compared understanding climate-worsened heat health impacts to the story of the blind men and the elephant, in which each man feels a different part of the beast, but none have the whole picture.

“I think of the temperature community as 20 to 30 years behind the air pollution community,” David Hondula, a temperature researcher at Arizona State University, told me. “There’s a lot to be done.”

Climate mandates mean that California officials are beginning to characterize heat across the state, not just in LA but also in the Inland Empire and the Central Valley. And heat doesn’t know borders. More people die in the United States each year from heat-related illnesses than from hurricanes or other natural disasters combined. Government responses, personal responses, public and private responses: They’re taking a lot of different forms, in a lot of different places.  

In Los Angeles, mayor Eric Garcetti has said he’s interested in cooling the city down, a project that will take at least a couple of years of study just to determine if it’s realistic. In the meantime, I’m interested in how people around the city’s heat archipelago are coping.