22m children face heat stress in Bangladesh

At least 22 million Bangladeshi children aged 0–9, or around 79% of children in this age group, are now experiencing at least one additional month of dangerous heat stress every year due to climate change, according to a study led by researchers at Vrije Universiteit Brussel (VUB).

The study found that the number of young children exposed to prolonged heat stress in Bangladesh has nearly tripled because of climate change, rising from around 9 million to 26 million.

Repeated exposure to extreme heat can have consequences beyond immediate health risks.

The study links overheating to potential impacts on learning and cognitive development, raising concerns for children at a stage when their bodies and brains are developing rapidly.

The researchers called for targeted adaptation measures, including heat-action plans and stronger public health systems, alongside reductions in fossil-fuel emissions that drive global warming.

VUB senior author Wim Thiery said protecting future generations requires urgent reductions in fossil-fuel emissions and efforts to keep global warming within the goals of the Paris Agreement.

Why young children are especially vulnerable
Children respond to extreme heat differently from adults. According to the researchers, children’s bodies heat up faster, they are less efficient at sweating and cooling themselves, and they depend heavily on adults for protection during extreme weather.

Prolonged heat exposure can lead to dehydration and heatstroke, worsen existing health conditions and affect learning and cognitive development.

Dr Shimul Mazumdar, Senior Consultant (Child) at General Hospital, Cumilla, said the effects of intense heat are increasingly visible among children.

“The impact of intense heat, worsened by climate change, is becoming increasingly evident among children,” he said, pointing to symptoms such as sudden vomiting, excessive fatigue, restlessness and loss of appetite.

The risks are particularly concerning in a country where children’s ability to escape extreme heat often depends on household conditions. Poverty, inadequate housing, limited access to cooling and overstretched health systems can leave children in developing countries with fewer options for protection.

What does ‘heat stress’ mean?
The study does not simply count days when air temperatures are high. Instead, it focuses on humid heat, which can be particularly dangerous because high humidity makes it harder for the body to cool itself through sweating.

The researchers used a wet-bulb globe temperature threshold above 28°C in the shade to identify dangerous humid-heat conditions.

This means temperature alone does not determine the level of heat risk. High humidity can significantly increase the stress placed on the body.

The researchers combined population data with climate models and climate-attribution methods to estimate how much additional heat exposure can be attributed specifically to human-induced climate change.

VUB described the study as the first global analysis to quantify climate-change-driven heat exposure across different age groups, both under current conditions and future warming scenarios.

Bangladesh part of wider South Asian heat crisis
Bangladesh’s situation reflects a broader heat crisis across South Asia.

Across the region, 167.4 million children aged 0–9, or around 62% of children in this age group, are currently exposed to at least one additional month of climate-change-driven heat stress.

The number experiencing at least five total months of heat stress has also nearly doubled, from around 80 million to 156.6 million.

Globally, the study estimates that up to 560 million children aged 0–9, or 43% of all children in this age group, are already experiencing at least one additional month of heat stress each year because of human-induced climate change.

This represents a higher level of additional exposure than for any other age group.

Rosa Pietroiusti, lead author and a PhD researcher at VUB, said children in developing countries face disproportionate exposure to climate extremes despite contributing the least to historical greenhouse-gas emissions.

She also highlighted poverty, poor housing, limited cooling options and overstretched health services as factors increasing children’s vulnerability.

The next few degrees matter
Bangladesh’s situation could worsen substantially if global temperatures continue to rise.

Under a 1.5°C warming scenario, the study projects that around 23 million Bangladeshi children, or 87%, would experience at least one additional month of heat stress each year. About 25 million, or 93%, could experience at least five total months of heat stress.

At 2°C of warming, exposure would become almost universal. Around 98% of Bangladeshi children aged.