Many Mass. students are returning to hot classrooms that could compromise their learning

Third-grade students sat in class on the first day of school at Paul Revere Innovation School in Revere.David L. Ryan/Globe Staff

Although beach days are winding down, the heat of summer temperatures will persist well into the first weeks of the school year. As Boston students return for their first day of school on Thursday, temperatures are expected to rise to 91 degrees. Elementary school-age children will soon crowd into classrooms for eight hours each day, expected to learn and retain critical information. But in Massachusetts, being inside does not necessarily mean that children are sheltered from the heat.

Many public schools in Massachusetts are in old buildings, like Mather Elementary School in Dorchester. Old school buildings like Mather do not have the infrastructure to accommodate central air conditioning and can often reach above 90 degrees in the first few weeks of the school year.

These sweltering temperatures can cause loss of learning, compromised sleep, and even heat stroke, according to pediatricians. Although the historical buildings can’t host central air as they are, pediatricians urge that updating the outdated infrastructure to accommodate cooling is necessary for children’s learning and well-being, especially as climate change brings hotter temperatures to New England.

“We really worry about the physical health of children when the temperature gets above 90 degrees,” said Dr. Scott Hadland, chief of adolescent and young adult medicine at Massachusetts General Hospital for Children. “We will see more of these days even in September as the climate changes and the effects in many US classrooms, especially in Massachusetts, which often don’t have air conditioning.”

The Mather School is among many public schools in Massachusetts that are without AC. Dianne Kelly, superintendent of Revere Public Schools, said that although most of the city’s schools are air conditioned, Revere High School is only partially air conditioned and teachers have to take turns using cool rooms on hot days.

“When we have really hot days in early September where temperatures might be in the upper 80s or 90s, it gets really hot on the upper level of the high school,” Kelly said. “We do have partial AC in the building; one wing is air conditioned, and on hot days teachers will rotate kids in and out of the air-conditioned rooms.”

A second grader at the Beethoven School in West Roxbury enjoyed a popsicle to cool off after gym class in this 2013 photo.The Boston Globe/Boston Globe

The Revere Public School district is currently working with the Massachusetts Building Authority to build a new high school that would have central air conditioning, Kelly said.

Boston Public Schools, the largest school district in Massachusetts with 46,001 students enrolled in 2022-2023, placed air conditioning — window units, portable units, and central air units — in every classroom in each of the 63 BPS buildings being used for summer learning in June, but that does not account for all BPS classrooms — 20 schools do not have air conditioning.

“There are 10 schools that will need major upgrades to their electrical capacity in order to accommodate increased energy demand from air conditioning,” Max Baker, press secretary for Boston Public Schools, said. “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.”

Daniel O’Brien, chief communications officer of Worcester Public Schools, which is the second-largest school district in the state, said that of the city’s 45 school buildings, 11 are fully air conditioned, six are partially air conditioned, and the rest do not have any air conditioning. O’Brien said the state’s lack of air-conditioned classrooms is because “many of the school buildings were built several decades ago when air conditioning was not common.”

In Brockton Public Schools all classrooms have air conditioning, according to chief marketing and communications officer Jessica Silva-Hodges.

Hadland said that when the temperature gets above 90 degrees, he worries about children suffering from heat stroke, particularly young children whose smaller bodies can easily overheat.

Lindsey Burghardt, chief science officer at Harvard University’s Center on the Developing Child, said that children’s learning abilities can suffer even at lower temperatures.

“The impacts on learning happen well below 90 degrees, but I would not be surprised if there are classrooms in Massachusetts that reach those temperatures, especially if there isn’t good airflow,” Burghardt said.

According to a study conducted by the US Environmental Protection Agency, the temperature for optimal learning performance is lower than 72 degrees. And student performance on psychological tests and school tasks increased by 20 percent if classroom temperatures are lowered from 86 degrees to 68 degrees.

Burghardt said that one of the mantras in pediatrics is that “children are not little adults,” and that is extremely relevant when it comes to how elementary school aged children’s bodies handle heat.

“Children can be affected by heat stress in multiple ways,” Burghardt said. “With extreme heat, children don’t sweat as much as adults where the adult body uses sweating to cool itself off. And if bodies can’t cool themselves, heat can bring on a variety of effects.”

Burghardt said that impacted sleep quality, mental health issues, slowed cognition, and inability to concentrate are all side effects of children being exposed to heat.

The implications of heat on students’ learning are most prevalent in northern states where schools are often inside older buildings that do not have AC, Burghardt said.

“Places that aren’t equipped to deal with changes in temperatures like Massachusetts, New York, or Vermont, are where you are going to see heat affecting performance most,” Burghardt said. “Not in places that are used to hot temperatures and have the infrastructure in place to mitigate heat for children, like southern states.”

In addition to learning loss, Hadland said that hot classrooms can make children feel tired, dizzy, faint, thirsty, and overheated, and they can experience nausea or vomiting, which are symptoms of heat stroke.

When children go to school all day in hot, unairconditioned classrooms and then go onto extracurricular activities like sports practices, Hadland said, it is important to take extra precautions.

“Sports activities that require physical exertion will be at best difficult and at worst dangerous if children don’t remain hydrated,” Hadland said. “There should be a strong focus around hydration and making sure children have snack breaks because they will be particularly susceptible to heat stroke after being in a hot classroom all day and then exert themselves after school as well.”

Hadland said students should plan to wear lightweight, loose-fitting clothing to school for the first few weeks to help mitigate extreme heat.

“It’s not just that children aren’t working hard enough, their environment is making it harder for them,” Burghardt said.