Too hot to handle: As schools reopen in a heat wave, a warning of the climate future

Older school buildings across New England are ill-equipped for extreme heat, which is becoming increasingly common

A fan was set up in the basement of the music room at the Mather Elementary School in Dorchester.David L. Ryan/Globe Staff

INTO THE RED: Climate and the fight of our lives

By the end of the day on Wednesday, students in Ralph Saint-Louis’s class at Lowell High School had had it. One put her head down, complaining of a migraine. Another asked for water, grateful for the mini-fridge that Saint-Louis, a science and ESL teacher, keeps stocked for moments like this.

As the temperature outside rose into the low 90s, classroom temperatures soared nearly as high. In Saint-Louis’s room, a standalone air conditioner he had raised money to buy himself was set to 61 degrees and still managed only to keep the temperature in the high 70s.

“Research out there says you need an appropriate and comfortable environment for student learning to be most successful,” he said. “And yet here we are.”

Across Massachusetts, schools are reopening for the year amid a heat wave — relentless heat, with temperatures well into the 90s in some places, giving a taste of what climate change is likely to deliver more frequently, more intensely, and more often earlier in the spring and later into the fall. Experts say that many schools across New England are not prepared for the heat, largely because they were built at a time when they didn’t need to expect it. Even as extreme heat has more often become reality, many districts have not adapted.

“This is the product of years of underinvestment in our school buildings,” said Sara Ross, cofounder of UndauntedK12, a nonprofit group advocating for climate-friendly schools. “Massachusetts schools are pretty ill-prepared for the extreme heat, especially in historically underinvested-in areas where buildings are older and don’t have modern HVAC solutions.”

Climate advocates and clean energy experts say the ultimate solution for cooling schools should be electric heat pumps, offering an efficient and climate-friendly way to both cool and heat buildings. But particularly in poorer districts and those with older schools, the pumps and extensive retrofits required to put them to use efficiently could be costly and years away. And this week, some schools were relying on window units, which can consume massive amounts of electricity.

That’s the case in Boston, where window units will be keeping most schools cool while the city works on a longer-term approach to converting its schools to heat pumps. More than 4,000 such units have been installed across 70 schools in the last two years, according to school district spokesperson Max Baker, and more will be installed as school begins Thursday.

A total of 13 Boston schools won’t have air conditioning at all, leaving students and teachers to face the stifling heat with no relief. Ten require major upgrades to their electrical capacity to meet the demands of air conditioning, meaning there is no short-term fix.

“We are continuing to work with our city partners to make these major investments in our school facilities to ensure all our students can learn in environments that are healthy and comfortable,” Baker said.

Jessica Tang, president of the Boston Teachers Union, said the window unit air conditioning in some schools has been greatly appreciated.

“But in our eyes, the job won’t be complete until 100 percent of classrooms have the necessary AC and electrical upgrades,” she said.

Window units may take the edge off the heat, but they don’t come close to solving the problem, climate advocates say. Kyle Murray, Massachusetts program director at the clean energy advocacy group Acadia Center,called them “a piecemeal approach” that “is bad for the environment and incredibly wasteful, both from a climate perspective and an energy burden perspective.”

According to BlocPower, a climate technology company focused on greening buildings, window air conditioners use up to three times as much energy as a heat pump to cool a building. But when it comes to upgrading Massachusetts’ school buildings, it can be complicated to switch over to heat pumps, which first require that buildings are weatherized and insulated and may necessitate major electrical upgrades.

When considering learning outcomes for students, experts say those steps are well worth the cost. In recent studies, Boston University economist Joshua Goodman looked at the educational toll of extreme heat and found that PSAT and scores on state primary school tests like the MCAS fall during hotter years.

“Not only did we see that heat had a long-term impact on the amount students would learn in a given year, but that those impacts were very unequal based on the income and race of the student involved,” he said.

When Goodman and his colleagues looked at where students most reported high heat getting in the way of their learning, the Northeast — with its many old schools, built for a cooler climate — stood out. “I think climate change might be having the biggest impact on learning outcomes in parts of the country that have been less well adapted historically,” Goodman said.

Slowly, districts are starting to take steps to change that, mostly by building new schools that are climate-friendly.

Acton-Boxborough, for instance, opened its Boardwalk Campus, home to two elementary schools and a pre-K program, in 2022 and district energy manager Kate Crosby said she’s been grateful to see how well it is working this week.

“We’re thrilled to have a space that is really well air conditioned, and that we can keep cool on a day like this,” she said.

But the Boardwalk Campus was new construction. Tackling the rest of the district’s older schools will be a longer, more involved process, Crosby said.

“Schools are in an incredibly difficult position as they have very limited budgets and have to make remarkably tough calls on priorities,” said Murray, of the Acadia Center.

Incentives from Mass Save and last year’s federal Inflation Reduction Act can help defray the costs, said Ross of UndauntedK12, bringing the price of heat pumps in line with — or below — the cost of conventional fossil fuel systems. But even for schools that aren’t ready to take that step there are other things, like adding window shades and limiting outdoor activities, that can help now.

But as their doors opened this week, some districts struggled to operate in the heat.

In Springfield, home to some of the hottest temperatures in Massachusetts, administrators had to call for early dismissal Wednesday and Thursday, and canceled after-school activities. Framingham and Worcester school districts announced early dismissal for Thursday.

In Lowell, where Saint-Louis works, the decision came through Wednesday afternoon: School would be canceled for the rest of the week.