Understanding and Addressing the Risks of Extreme Heat on Human Health
May 1, 2019
Extreme heat is often referred to as a “silent killer.” Its impacts are not starkly visible like the destruction caused by a flood or hurricane, but it can be equally catastrophic. For example, a 2010 heat wave in Russia killed an estimated 55,000 people. Exact numbers are hard to come by, as heat-related deaths are often underreported, with cause of death often attributed to health conditions caused by extreme heat (e.g. respiratory disease, stroke, etc.) rather than the heat itself.
Recognizing the gravity of heat impacts on human health, USAID is helping to build the heat-health knowledge base and support efforts to institutionalize and improve heat risk management. At the March Adaptation Community Meeting, experts from USAID’s climate office, the National Oceanic and Atmospheric Administration (NOAA), and the Red Cross Red Crescent Climate Centre shared their respective efforts to address the impacts of heat on human health, provided recommendations for mitigating those impacts, and engaged in dialogue with participants on what further actions are needed.
The frequency and severity of heat waves are expected to increase, but there are a range of solutions that can be simple to implement and effective if a solid foundation of cooperation and coordination between individuals and institutions is in place. By improving our ability to predict heat waves, communicate warnings and take appropriate action, impacts of heat waves can be greatly reduced. To help narrow the information gap, NOAA’s Climate Prediction Center (CPC) is examining historical temperature trends alongside extreme heat thresholds in Africa. The CPC has developed heat forecasting systems that provide the public with real-time, regionalized heat, weather and climate information.
Risk management systems can promote adaptive behavioral change by making accurate information about the relationship between heat and health accessible, especially when paired with reliable heat forecasts. In Ahmedabad, India, a heat-health action plan was developed and coupled with a heat early warning system. The action plan is triggered when the temperature reaches a certain threshold, and pinpoints roles and responsibilities of individuals and sector-specific institutions in the event of a heat wave. Public or private spaces that provide shade offer extended hours of relief. Officials managing hospitals, water systems, schools, and transport systems have defined responsibilities, employing their institutions’ resources to save lives. The USAID Heat Waves and Human Health report describes how this action plan can be modeled for other cities.
Cities are generally warmer than rural areas due to the heat island effect and even within cities, there can be variation of ambient temperature, causing some areas within cities to be warmer than others. For example, in Nairobi, Kenya, researchers at the Red Cross Red Crescent Climate Centre discovered that temperatures in Kibera – Africa’s largest slum and home to some 170,000 people – were consistently higher than the safety threshold, which is set for Nairobi at large based on the location of the city’s main meteorological observation station. Therefore, heat-health action plans should tailor actions to address the needs of the most vulnerable populations. Physical and social factors affect the vulnerability of individuals and groups and can include age, gender, economic status, cultural affiliation and residence location.
To promote knowledge sharing and technical innovation in building health resilience to heat extremes, and with support from USAID, the Global Heat Health Information Network (GHHIN) was launched in 2018. This forum promotes partnership building and global-to-local learning for heat-health risk reduction. By working collectively, heat-health practitioners, municipal officials, utility representatives and other stakeholders are better equipped to tackle the challenge of extreme heat.