Every school day, children breathe the air inside their classrooms and drink from water fountains. A changing climate is putting new pressure on both. Across several continents, researchers are examining how extreme weather affects students during the school day and what it means for their health and learning. Together, these risks show how climate change is turning ordinary educational environments into places where children’s health can no longer be taken for granted.
Extreme Heat and Interrupted Schooling
In 2024, UNICEF counted that in 85 countries, at least 242 million students’ schooling was disrupted by climate-related hazards. Heat was the main issue that led to school closures. In East Asia and the Pacific, Typhoon Yagi alone affected 16 million children. Almost 74% of the students affected lived in low- and lower-middle-income countries.
According to UNICEF, schools and education systems are largely ill-equipped to protect students from these impacts. The organization also reports that climate-focused education finance remains strikingly low. Additionally, conditions inside classrooms are changing.
Warm classrooms interfere with learning even on days when schools stay open. A 2025 PLOS Climate paper systematically reviewed seven heat studies covering almost 14.5 million students in 61 countries. In a large U.S. dataset, a 1° Fahrenheit rise in school-day temperatures over the prior year was associated with nearly 1% lower learning gains. Three of the studies found that heat hurt math performance more than reading. In India and South Korea, additional days of intense heat lowered math scores as well.
Some students are affected far more than others. In one international assessment analyzed by the review, the same heat event had roughly three times the effect on low-income students as on high-income students. Any one student’s loss looks small. Across many children and many school years, small shifts compound into measurable gaps.
Some schools can offer a partial answer through cooling. One U.S. study estimated air conditioning could offset about 73% of the heat’s cognitive impact on hot school days. Whether a child receives this relief depends on the school’s budget and building.
Indoor Air Quality and Student Health
The air inside school buildings deserves the same attention as air outdoors. Indoor levels of some pollutants can run two to five times higher than outdoor levels, according to the U.S. Environmental Protection Agency. Poor indoor air quality can affect student attendance and performance. The performance of teachers and staff can suffer, too.
Indoor allergens, such as dust mites and mold, can trigger asthma symptoms. The EPA says nearly one in 13 school-age children has asthma. The agency describes it as the leading cause of school absenteeism due to chronic illness. Around school grounds, diesel exhaust from buses and other vehicles is linked to worsened asthma and allergies.
Compared with adults, children are more exposed. Relative to body weight, they breathe more air, eat more food and drink more liquid. Their developing bodies may also be more susceptible to environmental exposures.
Mechanical systems shape these exposures. Older heating and cooling systems need more frequent repairs and inspections and can cause ongoing temperature and humidity problems. Newer components improve air quality and comfort and help reduce illnesses that disrupt learning. A school with a dated system may therefore struggle to maintain comfortable conditions during a hot spell or a smoky week.
Long-term exposure draws attention as well. A nationwide Danish cohort study tracked exposure for 785,312 students who took ninth-grade exit exams. Higher exposure to fine particulate matter, meaning tiny airborne particles, was associated with lower grade point averages.
The associations were stronger in math and natural sciences than in language subjects. The study framed its question around lifetime exposure. Among the cohort, girls were more affected. Such associations describe patterns across very large groups rather than proving cause. They point in a consistent direction nonetheless.
Drinking Water, Floodwater and Food Safety
After heavy rain, floodwater can carry pathogens from waste, including E. coli and salmonella. To evacuate or reach help, survivors may need to wade through rising water. After the rain stops, illness can still follow. Carbon dioxide emissions have also been linked to heavier precipitation and more natural disasters. For schools in flood-prone areas, the recurring question is whether water systems have been cleared and tested before students return.
Even without floods, rising temperatures matter for water-related illness. In Cape Town, South Africa, research linked rising temperatures to more diarrhea in children under 5, with monthly cases rising about 7.4% for each 1° Celsius increase during the November to May season. Cases fell substantially between 2010 and 2019. Local stakeholders credited sustained prevention and treatment programs. Their experience suggests that investment in basic water and health services can change outcomes for young children.
Even school meals depend on food safety systems under climate pressure. According to the World Health Organization, climate change is expected to increase the risk of foodborne disease through extreme weather and rising air and water temperatures. A shocking 29% of the health burden falls on children under 5 and is highest for children in low- and middle-income countries.
A cafeteria relies on dependable refrigeration. During heat waves or power interruptions, storage conditions become a fair question for any parent to ask. Many parents who choose ethically sourced groceries may have less visibility into how school meals are stored and sourced. For consumers who care about food ethics, school kitchens deserve the same scrutiny as any grocery shelf.
Uneven Risks and Available Solutions
Many of these findings point in the same direction. Students from low-income families are more affected by heat, and most children affected by climate-related school disruption live in lower-income countries. The UNICEF figures and the PLOS Climate review both show an uneven burden across and within countries.
Within a single district, older buildings and tight maintenance budgets deserve scrutiny as possible contributors. Publicly available facilities records, inspection reports and budget documents are a reasonable starting point for any family or community group asking where the gaps are.
Not every study measures the same thing. Large studies often rely on temperature or pollution estimates for an area rather than measurements inside each classroom. Some track test scores and others track illness. The findings are best read as a pattern rather than as a precise forecast for any single school. The direction of this pattern is consistent across heat, air and water.
Several of the mentioned responses have evidence to support them. Properly maintained cooling can offset a large share of the heat’s effect on learning. Well-maintained ventilation equipment supports healthier air. In Cape Town, sustained prevention and treatment programs were credited with a substantial decline in childhood diarrhea.
None of these measures is free, and priorities differ from one district to the next. Across the research, targeted investment in the building, the water supply and the kitchen appears to protect health and learning together.
Questions for Local School Boards
People should start with the maintenance records for heating and cooling equipment. A review of inspection schedules, filter replacement practices and plans for extreme heat reveals how prepared a building is. After any flood, a request for written confirmation of drinking water testing before students return is reasonable. Following a smoke event or a stretch of poor outdoor air, families can ask whether filtration or ventilation changes should follow. On the food side, kitchens can be asked about backup power and how temperatures are monitored in storage.
At public meetings, each of these questions is welcome. In writing, the questions leave a record for the next board. Priorities will vary across regions, with heat plans taking precedence in some districts and flood readiness in others. It is also fair to ask whether districts have schedules, shaded areas or cooling plans for the hottest days. Another reasonable question is whether results from water testing are shared with families.
Often, nurses and teachers see patterns in absences and symptoms first. Their observations can help shape better questions. When framed around shared goals such as comfort and health, the questions often open a more productive conversation than an accusation would.
Local newspapers and parent groups often track the same topics, and partnerships can widen the audience. Beyond these requests, advocates can also ask how the district tracks days lost to heat or smoke. Any district measuring the problem is better placed to prioritize repairs.
A Classroom Worth Protecting
The classroom is where society asks children to build their futures. It is now one of the places where climate change is felt directly. Across the evidence, heat, polluted air, contaminated water and unsafe food storage each carry documented risks for young students. Added cooling reduces the heat’s cognitive impact, and sustained prevention programs in Cape Town accompanied a large decline in childhood diarrhea.
Across communities, families and educators share the goal of keeping classrooms safe. The research offers a practical map for getting there. Careful attention to the building and the water supply can help turn a vulnerable space back into a safe one, starting with the questions a community is willing to ask out loud.