Extreme heat in Central and South America

The rise in extreme temperatures due to climate change is generating a direct impact on human health, ranging from dehydration, heat cramps, heat strokes, increased mental illnesses, to renal and cardio-pulmonary diseases, and even premature death. Moreover, extreme heat is also generating indirect impacts as it “can alter human behavior, the transmission of diseases, health service delivery, air quality, and critical social infrastructure such as energy, transport, and water” affecting labor capacity, productivity, food, and water supply access, among others. Extreme temperatures exacerbate the population’s vulnerabilities, affecting the elderly, children, people with co-morbidities, and those with low incomes more severely.

There is already much evidence of the impacts of extreme heat and heat waves in high-income countries. However, these countries have different climates, environmental conditions, socioeconomic characteristics, and vulnerabilities than those from Central and South America (CSA). CSA have existing inequalities that make them more prone to the adverse effects of extreme heat, such as high urbanization in poorly planned cities, lack of potable water, lack of sanitation and infrastructure, and high levels of poverty. However, the evidence on the health impacts of extreme heat in CSA is still limited.

This report is the result of a multidisciplinary work that aims to address the following objectives:

(i) understand how heat risk varies within the region and identify the countries and cities most at risk based on a combination of hazard, exposure, and vulnerability; (ii) recognize the known impacts of extreme heat in all countries; (iii) recognize the coverage of existing early warning systems for extreme heat; (iv) identify actors and organizations that are working on extreme heat in CSA; v) list significant heat wave events in the past (last 5 years); (vi) highlight priority gaps in heat risk knowledge for future research agendas; and (viii) highlight priority gaps in heat risk emergency action for future operational considerations.

Main findings

• CSA is exposed year-round to heat stress, nevertheless not all countries have the same heat risk. In Central America, Guatemala and El Salvador are the countries with the highest heat risk. In South America, Bolivia, Colombia, Ecuador, Guyana, Paraguay, Suriname, and Venezuela have the highest heat risk. These countries do not have clear heat action plans for these events, much less heat Early Warning Systems (EWS).

• Evidence on the risk and impacts of extreme heat and heat waves in CSA is limited to a handful of studies, mainly on health outcomes. Impacts on health care demands, the proliferation of vectors and infectious diseases, agricultural productivity, labor outcomes, occupational income choices, migration decisions, human capital accumulation, conflict, or political stability have not been extensively documented. However, limited evidence suggests that heat and increasing temperatures could affect all these outcomes that impact human well-being in CSA.

• Lack of consensus on the definition of a heat wave, health impacts of heat waves and, in turn, the pressure on the health systems, the identification of structural and social vulnerabilities, the quantification of the additive effects of exposure to simultaneous hazard and the lack of or limited heat EWS in most of the countries of the region are additional research gaps that emerged from key informant interviews.

• There have been important heat wave events from 2017 onwards; however, the region’s analysis of impacts on health is unclear.

• There are great challenges in dealing with heat risk emergencies. A major gap is that, in general, there are no multispectral and articulated national-level emergency heat risk action plans.