As the heat increases, the risk of gaining weight has been found to rise. This is attributed to the avoidance of outdoor activities and a lack of movement indoors. Extreme heat also threatens mental health. As temperatures rise, depression rates increase. There are opinions suggesting that measures like indoor exercise are needed to protect both body and mind from extreme heat.
A research team led by professor Akwasi Ampofo from the University of Adelaide in Australia noted, "It has been confirmed through a large-scale epidemiological study that the risk of obesity increases with prolonged extreme heat," in a paper published last month in the international journal 'Economics and Human Biology.'
The researchers analyzed data from over 19,000 participants in the Household, Income and Labor Dynamics in Australia (HILDA) survey. They also investigated the weather data from 2006 to 2022 in the participants' residential areas to examine its connection to obesity. Weather data was sourced from the European Centre for Medium-Range Weather Forecasts (ECMWF).
The analysis revealed that for each additional day when daytime temperatures exceed 30 degrees Celsius, the residents' body mass index (BMI) increased by 0.02%. Consequently, the risk of obesity also rose by 0.2%. The research team stated, "Temperature affects physical activity and induces obesity," adding, "It is essential to implement policies promoting indoor exercise during extreme heat."
Extreme heat also affects mental health. Researchers from the Catholic University of Korea's medical school's Department of Preventive Medicine, Seoul National University's Graduate School of Public Health, and Pusan National University's Department of Bio-Convergence Engineering stated, "There is a correlation between rising temperatures and depressive symptoms" in a paper published in the international journal 'Journal of Affective Disorders' in September of last year.
The researchers utilized data from over 219,000 participants in the 2021 community health survey. They compared how much higher the average annual temperature was in the regions where these individuals lived compared to the average (1961-1990). The study aimed to examine how temperature differences impact depressive symptoms.
According to that study, when the average annual temperature is 1 degree Celsius higher than normal, the number of people showing depressive symptoms increases by 13%. The research team explained that rising body temperature may influence depressive symptoms, suggesting that higher temperatures can increase stress levels and lead to sleep disorders. They stated, "Further research is needed on the impact of climate change on mental health."
References
Economics and Human Biology (2025), DOI: https://doi.org/10.1016/j.ehb.2025.101516
Journal of Affective Disorders (2024), DOI: https://doi.org/10.1016/j.jad.2024.08.187