AILSA CHANG, HOST:

California has topped heat records for a week now. Just yesterday, Sacramento hit 116 degrees. And this heat wave is straining the state's public schools, causing not just uncomfortable but potentially dangerous conditions for teachers, staff and about 6 million students. For more on how schools have been faring during this heat wave, we turn now to Kyle Stokes of member station KPCC. Hi, Kyle.

KYLE STOKES, BYLINE: Hi, Ailsa.

CHANG: All right. So you and I are both in LA where it has been insanely hot outside. Can we talk about, like, what conditions have been like inside schools here during the last few days?

STOKES: Yeah. It's - we've - well, as you know, Ailsa, we've had triple-digit heat here for a week. And in the Los Angeles Unified School District, heat is kind of a perennial issue. Complaints about broken air conditioning crop up even in more normal hot spells. At one point last week, the AC was broken or faltering in about 6% of the district's classrooms. But there's no air conditioning system at all in more than half of LA's school kitchens and cafeterias. So the labor union Teamsters Local 572 says food service workers have been laboring in triple-digit temperatures indoors. Union rep Adriana Salazar Avila received one report of kitchen temperatures topping 121 degrees.

ADRIANA SALAZAR AVILA: I had two employees get dizzy, and I had to sit them down. You know, do we have to have them pass out from heatstroke before we do anything?

STOKES: And then there's recess. Most LA schools, you know, they have very little green space, so there's little shade for students to seek refuge under - and scalding, scalding hot pavement.

CHANG: Exactly. So what are LA schools going to do to deal with this heat?

STOKES: Well, so the district is treating the kitchen temperatures as an emergency issue, promising to bring in heavier-duty cooling units, at least for now. At one point, the district also had more than 900 portable AC units running in classrooms with promises to buy even more. As for those hot recesses, over the long term, LA Unified is beginning to ramp up plans to install more green spaces on campus, which should mean more shade. But growing trees, you know, takes time.

CHANG: Yeah.

STOKES: And some parent groups and even the teachers' union want the district to explore shorter term solutions, like installing shade structures on play yards.

CHANG: Well, looking long term, Kyle, I mean, how much are California schools even built to handle this level of extreme heat that's probably going to get worse in the years to come?

STOKES: Right. I think we're learning many are not. Up the coast from LA, I actually talked with the school district in Ventura County, where the oldest schools used to lack air conditioning. And they used to be able to rely on a temperate coastal climate to keep schools cool. But now they're canceling classes or holding half days more regularly because of the heat. So they just passed a big construction bond to install AC. And then some schools simply have old systems. In Los Angeles, there are nearly 700 school campuses. And at 599 of them, the heating, cooling or ventilation system is at the end of its life or beyond, according to the district. One expert I talked to said that while there isn't good statewide data here in California, it's likely that many districts are also dealing with aging systems.

CHANG: But I mean, didn't the pandemic highlight all the problems with ventilation in schools? And then there was this, like, infusion of cash from the federal government to fix those problems. What happened to those efforts here in California?

STOKES: Yeah. Well, there was stimulus money available, but most chose to spend it on things like air filters and rewiring systems to circulate air constantly, even if they needed a new system, because replacement costs are so high. So this week actually, also, Ailsa, a teacher shared with me a picture of her classroom air filter. It was really dirty, covered in dark gray particles. And she said this was a sign that the AC in her classroom wasn't working very well. So in many ways, this is just the latest event, this heat wave, to highlight the problem of AC in schools.

CHANG: That is Kyle Stokes of KPCC in Los Angeles. Thank you, Kyle.

STOKES: You're welcome. Transcript provided by NPR, Copyright NPR.