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In her fifth grade class in a Los Angeles school, on a day when outdoor temperatures reached 116 degrees, the heat gave Lilian Chin a headache. The air conditioner in her classroom was broken. Her fingers felt numb and she vomited in class, according to her mother. The nurse wasn’t available, so she was sent back to her hot classroom.

By the time the school day was over and Lilian made it to her mother’s air conditioned car, she was exhausted and red-faced. At home, she vomited again and got a leg cramp. Veronica Chin rushed her 11-year-old daughter to an emergency room, where she was diagnosed with heat exhaustion — a serious condition that leads to a life-threatening heat stroke if not treated promptly.

When Chin called the school, Haskell Elementary STEAM Magnet, to complain about the broken air conditioning, she received an email that a repair ticket had been created. The San Fernando Valley school, in the Los Angeles Unified School District, had marked the repair a “low priority.”  (School officials did not respond to CalMatters’ questions when a reporter called and visited the campus.)

Chin was furious. “I’m trusting them with my children,” she said. “I’m thinking that my children are in a safe space, when they’re not.”

As climate change intensifies heat waves, California schools are unprepared to protect their students from extreme heat. Some schools don’t have air conditioning at all, because they were built before hotter climates made it a necessity. Others have old systems pushed to their limits, with school districts struggling to keep up with repairs or replacements with limited staff and funding.

For instance, in Long Beach — which reached a record high of 109 degrees last month — all or most buildings in 13 public schools with about 14,000 students have no air conditioning systems. In Oakland, as many as 2,000 classrooms don’t have them. And in Fresno, officials have been overwhelmed with more than 5,000 calls for air conditioning repairs in the past 12 months.

Between 15 and 20% of California’s kindergarten through 12th grade public schools “have no functioning heating and air conditioning systems at all, and as many as another 10% of schools need major repair or replacement for their systems to function adequately,” UC Berkeley and Stanford University researchers wrote in a report last year.  Some advocates say that is likely an underestimate.

School officials say they would need tens of billions of dollars to install and repair air conditioning. Many of the worst problems are in hot, inland school districts that serve low-income communities of color, where there are fewer financial resources to replace or repair them.

“If it’s too hot, just like if you’re too hungry, it’s almost impossible to learn, so the impact on students and teachers is great,” said Paul Idsvoog, the Fresno Unified School District’s chief operations officer. “If you have multiple systems that are 20 years old, sooner or later you’re not going to be able to keep up with the tide.”

Voters in November will be asked to approve a $10 billion school infrastructure bond to fund repairs and upgrades of buildings at K-12 schools and community colleges, including air conditioning systems.

Gov. Gavin Newsom last month vetoed a bill that would have created a master plan for climate-resilient schools, including an assessment of when air conditioning systems were last modernized. State officials currently do not collect data on air conditioning in schools.

Nationally 41% of school districts need to update or replace their heating, air conditioning and ventilation systems in at least half of their schools, according to a federal study.

In California, the problems are common statewide, jeopardizing children and teachers in inland as well as coastal communities.

“It’s just a hot mess,” said Aaron Kahlenberg, a teacher at Los Angeles Unified’s John F. Kennedy High School in Granada Hills. “When it was cool out, it worked, and when it got hot, it didn’t work. It got to be very frustrating.”

Absences rise and learning drops on hot days

Hot classrooms lead to more student and teacher illnesses and absences, and studies show that they reduce children’s ability to learn.

On a recent day in Oakland when outdoor temperatures reached 88 degrees, 8th-grader Juliette Sanchez felt sticky and hot in a stuffy room at Melrose Leadership Academy.

“For me it’s a lot harder to focus on what I’m doing,” Sanchez said. “Like, right now I’m sticking to the table. It’s uncomfortable to write. My arm is sticky and I’m just hot.”

Student performance on exams declines by up to 14% on hot days, according to a 2018 Harvard study in New York City. According to another study, an increase in the average temperature of 1 degree leads to 1% less learning, measured by changes in test scores.

For Black and brown students, the learning losses are even greater, said V. Kelly Turner, a heat expert at UCLA’s Luskin School of Public Affairs who has researched hot schools.

“They’re already perhaps in schools that don’t have enough teachers or enough supplies, and then put on top of that, they’re going to hot homes,” she said. “Maybe they don’t have any rights to install air conditioning systems. Maybe they live in mobile homes and have even fewer rights.”

A state program, called CalSHAPE, helps public schools improve air conditioning and water systems. Between 2021 and 2023, more than 3,800 schools were awarded $421 million to assess their systems, with 11 undertaking major repairs or replacements.

However, in August, state legislators considered eliminating the program as part of a plan to give utility ratepayers small rebates. Although the bill failed, the program has been closed to new applications since July. More than a dozen school districts have urged the state Energy Commission to reopen applications.

The attempt to gut the program worries school and environmental advocates, who say the state is failing to prioritize schools as climate change raises temperatures.

“For many schools, cooling is no longer just a nicety, but a necessity,” Jonathan Klein, head of UndauntedK12, an organization that supports schools transitioning to zero emissions to reduce greenhouse gasses, said in a statement. “Students and staff deserve safe, healthy, resilient school campuses that support teaching and learning amidst extreme weather.”

Fixing air conditioners: $9 billion in LA schools alone

Most students return to school in mid-August or early September, when much of the state suffers its most intense heat waves. Some also operate year-round.

In the San Fernando Valley region of Los Angeles, classroom temperatures reached into the mid 90s during an early September heat wave.

Teachers at several schools there told CalMatters that their requests for air conditioning repairs went unanswered or were slow to come. Portable units installed in classrooms were insufficient to keep temperatures comfortable enough for students to learn. Students were visibly lethargic from the heat. Some parents opted to keep their children home.

Kahlenberg, who teaches high school architecture, said he had asked for the air conditioning in his classroom to be repaired for weeks. By the time a heat wave hit in early September, it still wasn’t fixed. His classroom temperature reached 95 degrees.

“Everybody was tired,” Kahlenberg said. “I told them if they needed to take a break, that if they didn’t want to work, it was totally acceptable. I would just extend the project. But it just shouldn’t have to be like that.”

Kahlenberg said teachers told him about 20 other classrooms at his school also didn’t have working air conditioning during that heat wave.

A physical education teacher in another Los Angeles school said she spent weeks before the September heat wave trying to flag air conditioning problems in her office.  (The teacher wished to remain anonymous out of fear she would be disciplined for discussing the issue with CalMatters.)

Then, when the extreme heat came and the gymnasium temperature was too hot for the students, she and others informed the school. She said the school responded on the last day of the heat wave that students could sit outside in shade if they needed to. The suggestion dumbfounded her: Why would she have her students sit outside, where it was even hotter than in the gym?

All schools in Los Angeles Unified have air conditioners. But Krisztina Tokes, the district’s chief facilities executivesaid 50,000 faulty or aged units and pieces of equipment need to be replaced in the district’s more than 1,000 schools.

LA Unified, the largest school district in the state, has invested $1 billion to upgrade heating, ventilation and cooling systems in the last two decades, including $287 million for 20 projects that are currently under construction or being designed.

Tokes said officials work to keep students safe by following protocols when air conditioning breaks down, such as installing portable units or moving students to spare, air conditioned spaces. Outside, schools place portable misting fans and commercial-grade pop-up tents for shade.

School days were cut short in schools where district officials felt they couldn’t provide a safe learning environment. Air conditioning systems are also checked at the start of summer and again just before classes start. Teachers and staff are trained to identify and respond to signs of heat related illness, a district spokesperson said.

“Under no circumstance should there be a child or parent thinking their health isn’t being addressed,” Tokes said. “There were conditions that were beyond the district’s control.”

Replacing all air conditioners in the district’s schools would cost at least $9 billion, according to Amanda Wherritt, Los Angeles Unified’s deputy chief of staff.

“It’s really about financial resources,” Tokes said. “We do not receive enough money from the state to either repair or replace our systems.”

Even coastal schools are sweltering 

While many classrooms throughout the state have air conditioning, those that don’t are often in coastal areas. Many of these schools were built in the 1950s or 60s, before the warming effects of climate change had worsened heat waves.

In Long Beach less than a decade ago, 51 out of 84 schools didn’t have air conditioning in all classrooms. Since then, a $1.5 billion local facilities bond has helped the school district upgrade many of them.

But 13 schools, serving about a quarter of the district’s students, still won’t be fully air conditioned for at least another three years. One school, Poly High School, which has about 4,000 students, will undergo major renovations, including adding air conditioning, that won’t be complete until 2028, said Alan Reising, Long Beach Unified School District’s facilities and operations assistant superintendent. In the meantime, officials installed portable air conditioners and outdoor shade structures in many of the schools, Reising said.

Two young people walk past the front of Long Beach Poly High School in Long Beach, Tuesday, May 14, 2024. Photo by Thomas R. Cordova.

Some inland Long Beach neighborhoods experience five high-heat days a year when temperatures exceed 97 degrees.

“Arguably, we haven’t needed it,” Reising said. But now, he said, “with the obvious signs of climate change, we have more hot days we have to deal with every year. There’s no thought that it’s going to get better in the future, so the need for air conditioning now has become very obvious.”

In the Oakland Unified School District, about 2,000 classrooms in 77 schools have no air conditioners. In late September, outdoor temperatures reached 88 degrees; some Oakland neighborhoods have seven days a year that exceed 89 degrees.

Equipping those schools with air conditioning would be an expensive and complicated task that would cost at least $400 million, said Preston Thomas, Oakland Unified School District’s chief systems and services officer.

At Melrose Learning Academy in Oakland, students said the heat makes it hard to focus. Lyra Modersbach, an eighth grader who is a member of an environmental club at the school, said she has noticed temperatures getting hotter year after year. When she’s home, she can wear cool clothes and rest to beat the heat, but she can’t do that at school.

Modersbach said her school has a few portable air conditioners but if too many are on at once, they shut off.

The heat “is very distracting,” she said. “I’ve noticed having a harder time getting my work done or feeling frustrated.”

As members of the Youth Versus Apocalypse environmental club, Modersbach and Juliette Sanchez advocated for their school to stop using a gas boiler and invest in an energy-efficient heat pump that will provide air conditioning. The district will use funds from a 2020 $735 million bond measure to install heat pumps at their school next year.

Inland schools have little money to invest

While many inland schools are fully air conditioned, some don’t have air conditioning in their gymnasiums, cafeterias and multi-purpose rooms.

Many inland school districts, where 100-degree days are common, have far fewer financial resources than wealthier coastal districts, said Sara Hinkley, California program manager for UC Berkeley’s Center for Cities + Schools.

“Most of the spending on facility upgrades is based on local bond measures, which is based on your ability to levy property taxes,” she said. “So districts that have lower levels of property values per student are able to raise less money to upgrade their facilities.”

School districts in the Central Valley and the Inland Empire are among those that have invested less money because of lower property values and a smaller voter base to tap into, Hinkley said.

“There’s no environmental justice or climate equity imperative. That would take an active regulation to change how bond disbursements are made in the state,” said UCLA’s Turner. “The state could go a long way by investing in better technical assistance to communities to apply for these funds and focusing on priority schools.”

Fresno Unified School District, where 90% of students are on free or reduced lunch plans, recently invested $60 million in federal funds to replace or install air conditioning systems in some of its gyms, cafeterias and multi-purpose rooms, said Alex Belanger, chief executive over the district’s operations.

But the district needs about $500 million to improve its heating and ventilation systems, Belanger said.

Belanger said during heat waves, it’s “all hands on deck” to keep students cool. Staff work weekends and nights to repair air conditioning systems and the school provides temporary chillers and portable air conditioning if systems break down.

Idsvoog said the Fresno school district would like to invest in energy-efficient strategies such as building well-insulated schools with green space and oriented in a way that won’t absorb heat. But there’s simply no money to do so.

“The reality is it’s not going to get any cooler and resources will always be a challenge for any school district,” Idsvoog said. “Any assistance, grants or state funding that can support those efforts is more than welcome.”

CalMatters is a nonprofit, nonpartisan newsroom committed to explaining California policy and politics.