As global temperatures continue to climb, scientists and health experts are warning of a new and largely overlooked crisis — the effects of heat on the human brain. Research across multiple disciplines has revealed that rising heat is not only straining the environment and infrastructure but also damaging cognitive performance, mental health, and neurological stability across populations worldwide.
A sweeping global analysis of data from over 14.5 million students in 61 countries shows that exposure to prolonged high temperatures significantly reduces students' academic performance, especially in complex subjects like mathematics. This trend is particularly concerning as climate models predict a sharp increase in the frequency and intensity of heatwaves in the coming decades. According to researchers, cognitive decline begins at around 26 degrees Celsius, as the brain struggles to regulate itself under thermal stress.
Beyond cognitive function, the mental health impact is becoming increasingly severe. Higher temperatures have been linked to a sharp rise in cases of irritability, aggression, anxiety, and depressive episodes. Data indicates a worrying correlation between heatwaves and increased instances of violence, self-harm, and suicide. Vulnerable populations, such as those suffering from schizophrenia, Alzheimer’s, epilepsy, and other neurological disorders, are especially at risk as their symptoms tend to worsen with rising heat.
Children and unborn babies may face some of the most serious consequences. Exposure to extreme heat or environmental stress during pregnancy and early childhood has been associated with developmental disorders like ADHD and autism, reduced IQ levels, and increased chances of experiencing mental health challenges later in life. Additionally, prolonged exposure to air pollution — often made worse by heat — has been found to cause inflammation and damage to brain tissue, including markers associated with Alzheimer’s disease.
Hospitals and emergency rooms are also reporting a surge in visits due to heat-related neurological issues. Young children and the elderly are most frequently affected, with doctors noting spikes in cases involving migraines, stroke, and even meningitis during heat waves.
Experts warn that the full spectrum of heat's impact on brain health is still not fully understood, and more research is urgently needed. However, they are calling for immediate action. On the personal level, people are advised to stay hydrated, avoid outdoor activity during peak heat hours, and use fans or air conditioning whenever possible. Urban planning solutions such as green spaces, reflective building materials, and accessible cooling shelters can help protect entire communities.
Public health systems, meanwhile, must incorporate climate-related neurological risks into their planning and outreach. Increased investment in mental health services, early warning systems, and protective infrastructure is now seen as essential.
With projections showing that parts of the world, including densely populated regions like South Asia and the Middle East, may face five to eight times more extreme heat events by the end of the century, the challenge ahead is both urgent and global. If left unaddressed, the brain could become the next major casualty of the climate crisis.