A graphic illustration of a red plastic play slide, with the bottom of it melting into a puddle.

Produced by ElevenLabs and News Over Audio (NOA) using AI narration.

This year, just like last year, the nearly 200,000 kids in Chicago’s public elementary schools spent recess indoors during the first week of school, when the heat index hit 114 degrees. In the past few weeks, outdoor activities were canceled at schools in and around Washington, D.C., where temperatures exceeded 100 degrees last month, and in Southern California too. These schools have good reason to exercise caution: Kids are particularly susceptible to extreme heat, and in a tragic incident last year, a 12-year-old in California collapsed during P.E. and died on day two of an excessive-heat warning. A bill named after him—Yahushua’s Law—is currently on the governor’s desk and would require the state to set temperature standards for outdoor school activities, including recess.

As the first and last weeks of school keep getting hotter in some places, recess might be moved indoors day after day. But kids also need to be outside: Recess can improve grades and is where kids learn how to problem-solve and cooperate. The quickest way to keep playgrounds open through extreme heat is to get them out of direct sunlight; shade can make a person feel up to 72 degrees Fahrenheit cooler, researchers at UCLA have found. In the next few years, schools’ ability to install structures that provide artificial shade could determine whether recess survives June, August, and September.

To the extent that researchers have measured shade in schoolyards, they’ve found that most have next to none. In St. Louis, for instance, researchers found that, on average, the city’s elementary-school playgrounds were almost entirely exposed to direct sunlight. Some schools had no shade at all. In California, 91 percent of the average schoolyard has zero tree cover.

Playgrounds aren’t shadeless by accident: Many public playgrounds were designed to be treeless. In the 1980s, lawsuits over playground injuries made city planners start to see trees not as shade providers but as temptation for tree climbers who could end up with broken arms. Clearing trees in play areas was encouraged, as was replacing concrete and even grass with bouncier and less trip-inducing surfaces such as ground-rubber mulch and artificial turf, which trap heat. Metal and plastic equipment, which in many places are overtaking wooden playsets because they’re considered safer, add to the problem: They can get hot enough to cause serious burns.

Planting trees can help address heat, but generations of kids will graduate elementary school by the time trees planted now grow enough to make a difference. Shade structures—such as canopies of UV-resistant tarp—can take just days to put up. But installing shade can cost thousands, even tens of thousands, of dollars; the parent-teacher association at one Florida school fundraised to install a $17,000 structure, for instance. In Prosper, Texas—a Dallas suburb where students stay inside when the “feels like” temperature passes 100 degrees—installing a single UV-resistant tarp over an elementary-school playground cost more than $95,000.

Public schools and nonprofits can apply to the American Academy of Dermatology for up to $8,000 in funding for shade structures—which the group acknowledges won’t cover the full cost of many projects. Still, these grants are one of the only outside sources of funding for these projects. Dermatologists are invested in limiting lifetime sun exposure, much of which occurs in childhood, but in 2024 the group was able to give funding to just four schools.

Susan Godfrey applied three years in a row for the AAD’s grant when she was teaching in Robinson, Texas; her principal told her, she says, that the school just didn’t have the money to add shade to the playground. The kids in her class “wanted to go outside so badly,” she told me. But “after five minutes, their little faces were just beet red,” and they’d huddle, lethargic, under the one tree on the edge of the schoolyard. Winning the grant ultimately involved ginning up community engagement—in this case, handing out little bottles of sunscreen donated by local dermatologists at the town’s fall festival to raise awareness about sun exposure—but purchasing a shade structure still required money from the school district. Godfrey had originally hoped that the grant would help provide shade for the entire playground; in the end, the school had enough funding to cover the slide.

Some school playgrounds more severely lack shade than others. Jolee Potts, the dermatologist who led the St. Louis study, noticed that shade disappeared progressively from schoolyards as she drove from the suburbs to her hospital in the heart of St. Louis. In the study, she and her colleagues also found that, as the share of a school’s student population on subsidized lunch (a common proxy for child poverty) increased, shade cover on the playground decreased, on average. A similar 2024 study looked at tree shade more generally on the campuses of elementary, middle, and high schools in Austin and found that they lost roughly two basketball courts’ worth of shade for every 10 percent increase in school lunch-program enrollment. When schools are looking to make improvements, often by raising funds through bonds, “it’s very difficult to get heat-related issues covered” at all, Paul Chinowsky, the director of the environmental-design program at the University of Colorado at Boulder, told me—but “the wealthier a district, the easier it is.”

What federal programs do exist to help schools adapt to climate change right now focus on energy efficiency, or cover the cost of planning, but not executing, building modifications. Unless more resources emerge to underwrite shade, particularly those that don’t require winning a contest, “in many parts of the country, you are going to see school districts that are spending the first two weeks—even up to a month—with indoor recess. I don’t think we’re far away from that at all,” Chinowsky said. Extreme heat will keep bleeding into the school year. This month, Phoenix had its 100th straight day of 100-degree heat. The city started thinking about shade more than a decade ago. It’s falling behind on its goal to have 25 percent of the city shaded by 2030, but that it has a plan at all puts it ahead of many cities that are about as hot.

If kids do spend August and September recesses indoors, they’ll probably stay in the classroom. In warm areas, plenty of elementary schools haven’t invested in gyms because playing outside has been the default. “We’ll see more and more children in these communities having recess inside, in venues not appropriate for physical recreation,” Kelly Turner, a heat researcher at UCLA, told me. “They do things like watch movies” during indoor recess at her daughter’s school. Some teachers are using the extra classroom time to cram in more instruction; others put on dance videos that promise to “get the wiggles out.” But they can’t replicate the type of unstructured play that kids need as they grow. I remember a day in second grade when I felt for the first time like I had friends—we were playing tag, and they really chased after me. I’m sure I spent recess indoors some days that year, but I don’t remember them.