By Lucas Scherdel, Joy Shumake-Guillemot, Hunter Jones, Juli Trtanj, and Chao Ren
Extreme heat poses a serious and growing risk in all world regions, but heat-related deaths are largely preventable. The First Global Forum on Heat and Health, held in Hong Kong, China, from 17 - 20 December 2018, addressed this challenge and formally launched the Global Heat Health Information Network.
Over the four-day event, 120 interdisciplinary practitioners and researchers from 33 countries provided fresh, real-world perspectives on heat health risk management across diverse fields, including medical science, urban planning, meteorology and economics.
The first Forum enabled a global community of experts and practitioners to share experiences, identify priorities, and strengthen interdisciplinary cooperation to develop the capacity of governments, organizations, and professionals to protect populations from the avoidable health risks of extreme and ambient heat.
In her opening address, World Meteorological Organization Deputy Secretary General Elena Manaenkova said:
“The year 2018 was the fourth warmest year on record, one of 20 warmest years that have occurred in the past 22 years. Many parts of the world experienced exceptional heat, prolonged heat waves, and associated wildfires. Hot extremes will increase in the future and so the risk to human health. Heat warnings and related weather and climate services are critical to mitigate this risk. Therefore, WHO and WMO are taking urgent action and bringing health experts and meteorologists together to enhance heat-health services to the public.”
The key outcome of the Forum was the development of the Call to Action from the First Global Forum on Heat and Health. This document outlines the key messages, challenges, solutions and recommended actions to protect populations from the avoidable health risks of extreme ambient heat.
Key messages from the Call to Action include:
Heat stress is a serious and urgent health threat for humans;
Extreme heat waves are disasters;
All populations are affected by rising ambient temperatures, however, some populations are more vulnerable due to a combination of high exposure, physiological preconditions and socioeconomic status;
Occupational heat strain directly affects workers’ health and economic productivity;
Urban environments magnify heat exposure;
The mental health impacts of heat are an emerging area of interest;
Heat-related problems are destined to increase for decades to come.
The Global Heat Health Information Network was formally launched during the Forum as an independent, voluntary, and member-driven forum of scientists, professionals, and policy makers focused on enhancing learning and resilience building for heat health.
The Network will build partnerships, improve available evidence and actionable information for planning and preparedness, enhance global heat wave prediction capabilities, and promote life-saving heat-resilient interventions such as community outreach and early warning systems.
Moving forward, the Network will share recommendations with its partner organizations, including the World Meteorological Organization and World Health Organization, recognizing their importance in providing guidance for addressing these risks.
The diverse network of professionals from many fields in attendance - including medical doctors, meteorologists, architects, and urban designers - committed to work together to improve risk monitoring capabilities, including through meteorological information and health surveillance.
Global experts agree that extreme hot weather results in devastating consequences for human health in all inhabited world regions. Heat is a leading cause of weather-related death, and can result in permanent damage to the brain, central nervous system, and other internal organs exacerbating cardiovascular, respiratory, and psychological distress, injuries, and infectious disease.
Similar to hurricanes, tsunamis, and earthquakes, extreme heatwaves are disasters that can result in significant mortality and morbidity, as well as economic damages and destruction of property that can overwhelm response systems.
Heatwaves are increasingly accompanied by
cascading environmental or socio-economic impacts
from heat-triggered wildfires and drought, to food,
energy, water, and transport infrastructure failures.
The true global scale and magnitude of the impacts of
heat on society are recognized to be under-reported
Though all populations are affected by rising ambient temperatures, some are more vulnerable to heat stress and increased risk of death or illness due to a combination of high exposure, physiological preconditions and socioeconomic status.
High risk populations include the rural and urban poor, populations in regions that are already very hot and humid, regions with colder climates that are facing warmer summers, older adults, infants and children, pregnant women, indoor and outdoor labourers, athletes, attendees of outdoor events, and those with some pre-existing medical conditions. Occupational heat strain directly affects workers’ health, leading to loss of productivity and income.
Urban environments also magnify heat exposures, due to dense and vertical constructions, extensive use of heat retaining materials, limited vegetation cover, and heat generation from energy use in cooling and transport.
Research presented at the Forum shows that in highly urbanized and densely populated parts of the Hong Kong, every 1°C increase in maximum daytime temperature above 28.2°C results in a 1.8% increase in mortality. Experts note that the world could reach an urbanization level of more than 80–90% by the last quarter of the century, placing extremely large populations at risk.
The Global Heat Health Information Network is currently planning the 2nd Global Forum on Heat and Health. Subscribe to stay informed.
Lucas Scherdel and Joy Shumake
World Health Organization/World Meteorological Organization Joint Office for Climate and Health
Hunter Jones and Juli Trtanj
National Oceanic and Atmospheric Administration (NOAA) Climate Program Office
University of Hong Kong, Faculty of Architecture, Hong Kong, China