As record-breaking heat settles over communities around the world and Australia prepares for an intense El Niño summer, a new global analysis has identified a growing and often overlooked consequence of extreme temperatures: poorer mental health among children and young people. The study, published in the International Journal of Epidemiology, is the first systematic review and meta-analysis to examine how high temperatures and heatwaves affect mental-health outcomes in people aged 5 to 18.
The researchers analysed evidence from 23 studies conducted in different parts of the world, comparing temperature exposure with outcomes including anxiety, depression, emergency mental-health visits and suicide attempts. Their findings indicate that adverse mental-health outcomes rise by almost 1% for every 1 °C increase in daily temperature. During heatwaves, the risk was approximately 25% higher among children and adolescents, while exposure to generally higher temperatures was associated with an increase of about 1.5% in poor mental-health outcomes.
The analysis does not suggest that heat alone causes every mental-health crisis. Instead, it points to a complex interaction between environmental stress, physiological strain, disrupted routines and social pressures. Extreme heat can interfere with sleep, reduce opportunities for exercise and recreation, interrupt schooling and increase family stress. These effects may accumulate over several days, particularly when hot nights prevent the body from recovering from daytime exposure.
Children and adolescents may be especially sensitive because their bodies and behaviour are still developing. Young children have less control over their surroundings and may depend on adults to provide water, shade and cooling. Adolescents are undergoing major neurological, hormonal and emotional changes during a period when mental-health disorders commonly emerge. Heat can also affect concentration, impulse control and emotional regulation, potentially intensifying existing vulnerability.
“ There’s a range of reasons why children are more susceptible to changes in climate that are linked to social and developmental stressors, including disruptions to outdoor activities, their education, and recreational opportunities,” said Associate Professor Jacqueline Stephens, an epidemiologist at Flinders University and co-author of the study. She added that sleep disruption during hot nights can undermine wellbeing and emotional regulation, while caregiving stress and family conflict may increase during heatwaves and other extreme-weather events.
The researchers also highlight the connection between heat and learning. Higher temperatures have been associated with poorer academic performance, and overheated classrooms can make it harder for students to concentrate, process information and remain engaged. For young people already experiencing anxiety or depression, the loss of normal routines and safe social spaces may further reduce access to support. In this way, heat can operate as a “threat multiplier,” amplifying existing social, educational and psychological pressures rather than acting as an isolated risk.
The strongest reported effects appeared in developed countries. The authors suggest that this pattern may partly reflect urban heat islands, in which densely built areas absorb and retain heat, producing higher temperatures than surrounding regions. It may also reflect better access to mental-health services and more comprehensive reporting systems. Conversely, weaker associations in middle-income countries should not necessarily be interpreted as evidence of lower vulnerability. Limited healthcare access, underdiagnosis and under-reporting could conceal substantial impacts.
Corey Bradshaw, a global ecologist at Flinders University and co-author of the review, said that the findings support integrating mental health into climate-adaptation planning. He noted that children and young people may be less likely to adopt protective behaviours during dangerous heat and may face physiological and behavioural limitations that increase their exposure. The authors argue that large-scale interventions should accompany heat-health warnings, including mental-health support and targeted assistance for families during prolonged hot periods.
Dr Syeda Hira Fatima of the University of Canberra’s HEAL Global Research Centre and affiliated with Flinders University said the next step for Australia is to determine where and how children encounter heat in their daily environments. Potential measures include cooler classrooms, improved ventilation, shaded play areas and better-designed buildings. However, the researchers stress that these adaptations should be evaluated scientifically to establish whether they produce measurable improvements in mental health and wellbeing, rather than simply lowering indoor temperature.
The authors caution that evidence linking heatwaves specifically to mental-health outcomes remains limited and should be interpreted carefully until more studies become available. Differences in study design, climate, healthcare systems and definitions of heat exposure make direct comparisons difficult. Even so, the global synthesis shows that extreme heat is not only a physical-health threat. As climate change makes severe heat more frequent and intense, protecting children will require public-health strategies that address sleep, education, family stress and psychological wellbeing alongside dehydration, heat exhaustion and other established dangers.
Subject of Research: People
Article Title: First global synthesis of heat-related mental health impacts in children and young people: a systematic review and meta-analysis
News Publication Date: 4 August 2026
Web References: https://academic.oup.com/ije/article/55/4/dyag121/8741913; https://doi.org/10.1093/ije/dyag121
References: Kwan S, Stephens J, Bradshaw CJA, Varghese BM, Thompson K, Judge MA, Le Souëf PN and Fatima SH. International Journal of Epidemiology. DOI: 10.1093/ije/dyag121
Image Credits: Flinders University
Keywords: extreme heat, heatwaves, children, adolescents, mental health, climate change, anxiety, depression, sleep disruption, public health, Australia, El Niño, systematic review, Flinders University
