DHAKA - Hena Khan, a grade nine student in Dhaka, has struggled to focus on her studies this week as temperatures surpassed 40 deg C in the Bangladeshi capital.

“There is no real education in schools in this punishing heat,” she said. “Teachers can’t teach, students can’t concentrate. Rather, our lives are at risk.”

Hena is one of more than 40 million students who have been shut out of classrooms in recent weeks as heatwaves have forced school closures in many parts of Asia and North Africa.

As the climate warms due to the burning of fossil fuels, heatwaves are lasting longer and reaching greater peaks as average temperatures rise. In turn, government authorities and public health experts across the world are grappling with whether to keep students learning in hot classrooms, or encourage them to stay home and keep cool.

Either decision has consequences. About 17 per cent of the world’s school-aged children are already out of school, according to United Nations data, but the proportion is larger in developing countries, with nearly a third of sub-Saharan Africa’s children out of school against with just 3 per cent in North America. Children’s test scores in the developing world also lag far behind those in developed countries.

Heat could make that worse, widening learning gaps between tropical developing nations and developed countries, experts said, and even between rich and poor districts in wealthy countries. But sending children to overheated schools could make them sick.

South Sudan already in 2024 shuttered its schools to some 2.2 million students in late March when temperatures soared to 45 deg C. Thousands of schools in the Philippines and in India followed suit in late April.

Meanwhile, Bangladesh continues to waver between opening and closing schools for some 33 million children amid pressure to prepare students for exams – even as temperatures climb to dangerous levels.

Many of the country’s schools “don’t have fans, the ventilation is not good, and they might have tin roofing which does not provide good insulation”, said Mr Shumon Sengupta, Bangladesh country director for non-profit Save the Children.

On April 29, one day after reopening schools that had been closed in the previous week due to heat, the Bangladeshi authorities again closed all primary schools and educational institutions in nearly half of all districts as temperatures reached 43 deg C.

Hotheads

Even if students continue attending classes during heatwaves, their education is likely to still suffer. High temperatures slow down the brain’s cognitive functions, lowering pupils’ ability to retain and process information.

US high schoolers, one May 2020 study found, performed worse on standardised tests if they were exposed to higher temperatures in the year leading up to the exam.

The research, published in the American Economic Journal, found that a 0.55 deg C warmer school year reduced that year’s learning by 1 per cent.

Much of that impact disappeared in schools that had air-conditioning, said study co-author Josh Goodman, an economist at Boston University.

Somewhere between 40 per cent and 60 per cent of US schools are thought to have at least partial air-conditioning, according to various surveys.

Schools that do not are typically found in lower-income districts that already lag behind their wealthier counterparts academically. In the US, the average performance of the lowest-income students is about four years behind the highest-income students, according to a 2019 study in the National Bureau of Economic Research.

Mr Goodman and his colleagues found a similar learning pattern when they looked at standardised test data in other countries.

“When (students in) these places experience a year with more heat, they appear to have learnt less,” he said.

That is worrying, Mr Goodman added. “Climate change will widen the learning gaps between hot and cool countries.”

Some research suggests excessive heat in the tropics can impact a child’s education even before birth.

Children in South-east Asia exposed to higher-than-average temperatures in utero and early in life obtained fewer years of schooling later in life, a 2019 study in the Proceedings of the National Academy of Sciences journal found.

With many people in the region dependent on farming, high temperatures could hurt food production and household incomes, said study author Heather Randell, a sociologist at the University of Minnesota.

If crops are damaged by heat, young children may not get enough to eat which can stunt their development, she said, and a family may no longer be able to afford school fees, or could even pull children out of school to help on farms.

School rules

The number of days that schools are closed for extreme heat have been ticking up in the US, but few countries track such data.

US schools are now cancelling class for an average of six to seven school days each year for heat, compared with about three to four days a decade ago, said Mr Paul Chinowsky, a civil engineer who led a 2021 study on schools and rising temperatures for the firm Resilient Analytics, which consults for governments and non-governmental organisations.

In Bangladesh, “last year, schools were closed for six to seven days”, said Save the Children’s Mr Sengupta. “But this year, they are saying it might be closed for three to four weeks.”

May is generally the warmest month of the year in South Asia.

More closures worry him, Mr Sengupta said. When children are not in school, they are more vulnerable to child labour and child marriage, according to reports from NGOs.

Bangladesh Education Minister Mohibul Hasan Chowdhury said on April 30 that schools would be kept open on weekends if needed to complete the curriculum.

Decisions on school closures, he added, will no longer be a national directive but are to be made at the district level. REUTERS