Residents of the Cape Coral Shores memory-care facility in Florida are without power in the wake of Hurricane Irma. (Michael S. Williamson/The Washington Post)

It has been big news that millions of people are suffering without air conditioning in states hit by Hurricanes Harvey and Irma. High temperatures are not only creating miserable conditions — they’re also endangering health.

What’s not big news? That schools in the Orinda Union School District in California just closed temporarily because temperatures were above 100 degrees, and they don’t have air conditioning — ever. Or that scores of schools in San Diego and in Oregon and Washington just released students early because classrooms bereft of air conditioners were sizzling in record temperatures. Or that in June, schools in at least 20 New Jersey districts sent students home early in the heat, and the same thing happened in other states.

Every school year, thousands of classrooms sizzle in high temperatures with only fans (if they even have them) to circulate the (hot) air — even though research shows that indoor climate is an important factor in people doing their work well.

And decades of research have shown a connection between school performance and temperature. A 2017 Harvard University study looked at 4.5 million high school exit exams from New York City and found that “hot temperatures exert a causal, statistically significant, and economically meaningful impact on student outcomes by reducing performance on high-stakes exams as well as possibly reducing the amount of learning achieved over the course of the school year.”

The renowned Lawrence Berkeley National Laboratory cites research from decades ago that found student performance in reading speed and comprehension and in multiplication was much poorer — as much as 30 percentage points lower — when the temperature was between 81 and 86 degrees compared with when it was 68 degrees. Other studies found that students did worse when the room was at a low of 62 degrees than when it was set closer to 80, though students worked more slowly in the warmer temperatures. Later studies found the same pattern, though with different temperature thresholds.

This comes as no surprise to teachers and students, who are expected to show up at school and do their work no matter how hot or cold it is in their classrooms.

Indoor air quality has been given short shrift by school reformers, who have focused on test scores and curriculum standards as key mechanisms for academic improvement. When Chicago public school teachers went on strike in 2012, one of their demands was that schools be air-conditioned — and some people ridiculed them, even though temperatures in the summer can soar.

A story on the 74, an education website, found that in 11 of the country’s biggest school districts — some with consistently warm temperatures and others with temperature spikes — many schools and classrooms have no air conditioning. And many of those with air conditioning have systems in less-than-stellar shape. A 2014 study by the U.S. Education Department’s National Center for Education Statistics, with data from the 2012-2013 school year, found that 30 percent of district-level staff across the country rated their heating, air-conditioning and ventilation systems as being in fair or poor condition.

Teacher Sara Mosle wrote in the New York Times:

My first year as a public school teacher, I taught at Manhattan’s P.S. 98, which did not have air-conditioning. From mid-May until June’s end — roughly 17 percent of the school year — the temperature in my classroom hovered in the 80s and often topped 90 degrees.

Students wilted over desks. Academic gains evaporated. Even restless pencil tappers and toe wigglers grew lethargic. Absenteeism increased as children sought relief at home or outdoors. By day’s end, my hair was plastered to my face with perspiration.

It seems obvious: schools need to be cool. It’s absurd to talk about inculcating 21st-century skills in classrooms that resemble 19th-century sweatshops.

It’s not just the temperature that can affect school performance. Studies have made a link between student achievement and building quality, noting that children perform better when they are in classrooms with regulated air, windows that open, air that doesn’t emit foul odors, paint without lead and walls without asbestos.

It has long been known that temperature can affect not only performance but also health in the workplace and at school. In 1931, the New York Commission on Ventilation, trying to determine what air temperature was healthiest for students, conducted experiments in city and rural schools. In a 2002 report detailing this work, Glen Earthman, a professor at Virginia Polytechnic Institute, wrote:

Students were subjected to varying temperatures while in the classroom and measures of the number of reported illnesses were taken to compare with the temperatures. The commission reported that when classrooms are not maintained within the narrow band of temperature and humidity tolerances of 67 to 73 degrees and 50 percent relative humidity, there were more reported cases of student illnesses than students in a properly controlled thermal environment. The results of the commission study confirmed earlier studies conducted in the workplace that found excessively high temperatures tend to produce harmful physiological effects on workers. That part of the study that dealt with overheating showed that 15 percent less physical work was performed at 75 degrees than at 68 degrees with humidity at 50 percent; while at 86 degrees with 80 percent humidity, the decrease was 28 percent as compared to that performed at 68 degrees with humidity at 50 percent. Despite the age of this research, these findings are just as germane today as they were three quarters of a century ago.

Surely there will be those who will say that kids have gone to school for many years — and around the world — in the heat and get their work done. Mosle noted in her piece that Michael Bloomberg, when he was mayor of New York City, made that argument during a heat wave, yet officials in cities commonly warn the young and the old to find a cool place to shelter for health reasons when the heat rises too high.

And when American cities lose power in storms, the importance of air conditioning to sustained high-quality work is recognized. Here’s part of a Washington Post story in the aftermath of Hurricane Irma, which left millions of people without power in Florida:

Any disaster that wipes out electrical service hits especially hard in the South, where tens of millions of Americans rely on the cocoon of comfort provided by air conditioning. Without it, many cities could barely exist, let alone prosper. When the lights go out in Florida, the muggy, buggy reality can be jarring even to longtime residents.

There were signs on social media that some people were growing angry and tired of waiting. Others steeled themselves for an extended period without electricity.

The air conditioning will, thankfully, go back on for millions of people, but many schools will continue to face extreme temperatures inside classrooms and offices. Just don’t expect it to make big news.