Hot weather and heat extremes: health risks

Abstract

Hot ambient conditions and associated heat stress can increase mortality and morbidity, as well as increase adverse pregnancy outcomes and negatively affect mental health. High heat stress can also reduce physical work capacity and motor-cognitive performances, with consequences for productivity, and increase the risk of occupational health problems. Almost half of the global population and more than 1 billion workers are exposed to high heat episodes and about a third of all exposed workers have negative health effects. However, excess deaths and many heat-related health risks are preventable, with appropriate heat action plans involving behavioural strategies and biophysical solutions. Extreme heat events are becoming permanent features of summer seasons worldwide, causing many excess deaths. Heat-related morbidity and mortality are projected to increase further as climate change progresses, with greater risk associated with higher degrees of global warming. Particularly in tropical regions, increased warming might mean that physiological limits related to heat tolerance (survival) will be reached regularly and more often in coming decades. Climate change is interacting with other trends, such as population growth and ageing, urbanisation, and socioeconomic development, that can either exacerbate or ameliorate heat-related hazards. Urban temperatures are further enhanced by anthropogenic heat from vehicular transport and heat waste from buildings. Although there is some evidence of adaptation to increasing temperatures in high-income countries, projections of a hotter future suggest that without investment in research and risk management actions, heat-related morbidity and mortality are likely to increase.

Climate Change and Children’s Mental Health: A Developmental Perspective

“…Of the 20 warmest years on record, 19 have occurred since the year 2000 (U.S. National Aeronautics and Space Administration, 2020). Heat waves and hotter average temperatures increase health morbidity (Ebi et al, 2021) and are associated with increased risk of obstetric complications, preterm birth, and stillbirth (Barreca & Schaller, 2020;Bekkar et al, 2020;Poursafa et al, 2015). Obstetric complications are an established risk factor for several major neurodevelopmental and psychiatric disorders and can also affect typical psychological development in the absence of psychiatric diagnosis (Dalman et al, 1999;Glasson et al, 2004).…”

Health risks of extreme heat

“…Critically, although direct causes of death such as stroke or cardiomyopathy had a J-shaped relation with temperature in this study (increased risk at both extremes), the risk of external causes of death such as homicide or suicide rose monotonically as temperatures increased 11. If current trends continue, heat thresholds for maintaining health are likely to be exceeded far more often,3 resulting in further heat related morbidity and mortality 7…”

“…Heat related vulnerabilities are exacerbated by chronic conditions such as cardiovascular disease, respiratory diseases, diabetes, and hypertension and by behaviours such as alcohol consumption, misuse of illegal substances, and inadequate fluid intake 7. All are exacerbated by social and economic inequality.…”

“…Important physiological changes occur in response to high temperatures, and these are amplified by humidity. For example, blood flow is redistributed to the skin, sweating increases,6 and adjustments occur to the circulatory (such as vasodilation), nervous (autonomic activation), and respiratory systems (in response to increased oxygen demand) to maintain optimal body temperature; changes also occur in the renal system to maintain fluid and electrolyte balance and organ perfusion 7…”

Health Risks to the Russian Population from Temperature Extremes at the Beginning of the XXI Century

“…It is well-known that urban temperatures increase dramatically because of climate variability. The main reasons could be expressed as follows: artificial heat from urban transport system, other industrial activities due to the consumption of fossil fuels; heat flow from buildings; replacement of natural land cover by artificial with different thermal properties; population growth and population ageing, which is manifested in Urban Heat Island effect [63,76,85,127,128,140,157,158,202]. Whilst excessive urban heat from UHI aggravates the effect of extremely high temperatures on human health, cold is estimated to play an equally important role [157,158].…”