(The Hill) — Student learning and test scores are shown to fall when children are faced with extreme heat, a worrying sign as heat waves and rising temperatures become the norm in the U.S.

During this past week, millions of students went back to school even as the Pacific Northwest faced an unprecedented heat wave that is suspected of killing three people. 

The persistent soaring temperatures, especially in areas unfamiliar with them, disproportionately impact children in rural or low-income areas where school districts may not have adequate air conditioning.

“My colleagues and I have a couple of studies where we find that hotter temperatures during the school year affect the rate of learning,” said Jisung Park, assistant professor in the Department of Public Policy at the UCLA Luskin Center for Innovation.

“When we look at how more days above 85 and more days above 90 in the school year, it affects test scores. We find that it actually reduces the rate of learning,” he added.

The predicament heightens the already extraordinary learning gap students brought back after COVID-19 and remote learning.

The latest scores from the National Assessment of Educational Progress (NAEP) showed 13-year-olds’ average reading scores are at their lowest point since 2004, and average mathematics scores have gone down to levels last seen in 1990.

Extreme heat negatively affecting student outcomes has been well documented for years, but climate change is driving the problem to new heights — and new locations.

In 2020, Park, along with two other colleagues from Standford University and Boston College, released a study analyzing heat and learning outcome data from 58 countries. The report showed hot temperatures can not only disrupt students on test days but can negatively impact learning in the longer term. 

“It’s a bigger effect for minority and lower-income students, possibly, because they don’t have as much air conditioning or other cooling access either at home or at school,” Park said. 

The data on the effects air conditioning can have in combating hot days is more limited, partly because so is the data regarding air conditioning in U.S. schools. However, it is well known that school districts in poorer and rural regions are less likely to have adequate school infrastructure and air conditioning. 

“Unfortunately, maybe not surprising in this country that lower-income Americans have less air conditioning in the schools, but what they were able to do is then show that this contributes substantially to the racial gap in test scores or educational achievements,” said Marshall Burke, associate professor at the Doerr School of Sustainability at Standford University.

In an EdWeek Research Center survey back in 2021, it was also shown there were high disparities in which regions in the U.S. had air-conditioned schools. 

Eighty-eight percent of district leaders and educators in the South said all their school buildings had air conditioning, whereas only 20 percent in the North were able to say the same thing, according to the survey. 

The lack of good air conditioning in northern school districts has resulted in some students not being able to go to class as temperatures increase, most commonly at the beginning and end of the academic year.

In June, some schools in Michigan and Pennsylvania closed or went to remote learning for a few days due to extreme heat. 

And the phenomenon will likely only get worse. 

More than 100 million Americans over the summer faced extreme heat warnings, ranging across regions throughout the U.S.

“I think with climate change we should expect the exposure to get worse,” Burke said. 

Policymakers need to tackle the “very hard problem” of mitigating climate change while also implementing policies to ensure “students are protected when temperatures do get hot” such as updating school infrastructure and air conditioning, according to Burke.

However, experts caution against the situation being seen as a “doom and gloom” scenario with no possibility of improvement. 

Park said the data “also suggests that with smart policies, these effects can be mitigated pretty effectively. Again, whether that’s air conditioning or something else, I think it’ll depend on the local circumstances.”