High ambient temperatures and mental health: risks, methods and results

This work is an analytical review. Initial research data have been taken from original studies published in peer-reviewed scientific journals in 2014-2024. The following search terms were used when searching for English language sources in PubMed database: (mental health OR mental disorders OR mental illness OR suicide) AND (high ambient temperatures OR heat stress OR hot weather OR heat waves). Russian language sources were sought in eLibrary using the following keywords: mental health; mental disorders; mental diseases; suicide; high ambient temperatures; heat waves; global warming. The review has established the following. Effects produced by high ambient temperatures on mental health have only recently become a separate research topic within a broader context of ‘Climate Change and Population Health’ studies or, as the WHO terminology puts it, ‘Population Health under Changing Climate’. In contrast to five previous reports, the Sixth Assessment Report of the Intergovernmental Panel on Climate Change contains a bigger section on impacts exerted by climate on mental health. Scientific evidence suggests with high confidence that exposure to high ambient temperatures and heat waves causes mental disorders. These disorders include anxiety, depression, acute post-traumatic stress, suicidal behavior, and use of psychoactive substances; they are diagnosed as both mild disorders and severe cases that require hospital admission. Effects of heat stress on human psyche are caused by complex interactions between physiological and psychological factors. The human body tries to maintain the thermal balance and this induces a whole cascade of physiological reactions, ranging from increased heart rate to dehydration. Physiological strain undermines mental health and causes sleep disorders, irritability, mental fatigue and cognitive disorders.