Extreme heat is not just uncomfortable weather – it is becoming a serious threat to health, jobs and food security across southern Africa, especially for those least able to cope.
Unlike floods, cyclones, wildfires or hurricanes, extreme heat rarely leaves dramatic images of destruction. But it builds without relief and puts pressure on people's bodies, homes and health systems.
In many cases, the risk increases when temperatures remain high overnight, leaving little chance of recovery.
Even temperatures that seem manageable can be dangerous, depending on where people live and how well they can adapt.
We are members of a group of researchers and practitioners from Southern Africa working on climate, health and policy.
We recently conducted a regional consensus study for South African Academy of Sciences (ASSAf) To assess how extreme heat affects health and daily life across the region. Our objective was to determine what practical steps need to be taken to reduce harm from extreme heat.
We worked with a team of independent experts from across disciplines to review scientific evidence, regional data and policies and develop a shared, evidence-based view of how extreme heat is affecting the region.
our study was unique because it brought together evidence from health, labour, food systems and infrastructure to show how heat affects everyday life, analyzing heat not just as a weather phenomenon, but as a system-wide risk.
We found that extreme heat is already a threat to climate and health in southern Africa.
One of the biggest mistakes in public discussion is treating heat as merely a weather phenomenon. It is much more than that. Heat immediately increases the risk of dehydration, heat exhaustion and heat stroke. Heat can also worsen existing conditions such as cardiovascular, respiration And kidney disease.
There is a need to treat heat as a major public health and development priority across the world Southern African Development Community.
Heat is a health problem – not just a weather problem
The Southern African Development Community consists of 16 member states, home to more than 400 million people. Yet collectively, these countries contribute less more than 1.3% of the global greenhouse gas emissions.
Despite this, southern Africa is already warming rapidly. The average surface temperature over the entire area is raised by 1.0-1.5°C since 1961. A Further increase of 4.5-5°C This is projected up to 2050 under high-emissions scenarios (where fossil fuel companies continue to pollute at the same rate as they are now).
In our report, we describe extreme heat as an “integrator threat” (a multiplier). This means that it is not only a risk but also makes existing problems worse all at once.
For example, extreme heat can reduce crop yields and nutrient quality, increase water scarcity, degrade air quality through dust and wildfire smoke, and disrupt livelihoods that depend on safe outdoor work – all at the same time. This is what makes heat so dangerous.
This could make already hot environments – especially informal settlements with limited shade, ventilation or cooling – even more dangerous. it may be extremely hot additional stress On power systems. This increases the risk of power outages at a time when cooling, water supply and health services are most needed.
In many communities, heat also reduces the shelf life of perishable food – including informally sold food that is not stored in a refrigerator. This too increases risk Of food borne illness. This matters in a region like Southern Africa where street food and informal food economies are part of everyday life.
The burden is deeply unequal
Extreme heat does not affect everyone equally. One of the central findings of our study is that the people and communities most exposed to heat are often those with the fewest resources to adapt. This includes people living in informal settlements, those without reliable electricity or cooling, communities facing water scarcity, and workers who have to work outside all day.
In much of southern Africa, many people work outdoors or in poorly ventilated environments – from subsistence farms and construction sites to factories, markets and transport hubs. Being forced to slow down, stop work, or continue working in dangerous conditions due to heat affects both health and livelihoods.
Exposure to heat affects daily life: children may walk long distances to school or spend hours outside. It affects pregnancy and the health of the newborn baby, posing a risk Such as premature birth, low birth weight and pregnancy complications.
For this reason, extreme heat is also a moral and justice issue. The people who contribute the least to climate change are often the ones most affected by its impacts – simply because of where they live, what they work for, and what resources are available to them.
What should governments do now
Extreme heat is not a problem that can be solved simply by telling people to “drink more water” or “stay indoors” – especially where safe housing, water, electricity and cooling are not guaranteed. but there are practical solutions Which can be taken by governments and institutions.
These include:
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Improving locally appropriate early warning systems
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Tracking heat-related illness and deaths to guide response and planning
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Making clinics and hospitals more climate-resilient through reliable power, cooling, water supply and backup systems
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Protecting workers through rest breaks, shaded areas, access to water, and adjusted work hours
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Improving urban design and housing to keep buildings and neighborhoods cooler
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Integrating heat into national climate and health planning.
Governments can also set up public cooling spaces – such as community centres, schools or clinics – where people can rest safely during extreme heat.
There are already promising examples in this area. South Africa has began to strengthen Heat-health early warning and monitoring system. malawi is helping farmers Adapt to rising temperatures in climate-smart agriculture plan.
namibia has supported Community-level water and resource management in heat-prone areas. These examples show that progress is possible, but it needs to be extended and sustained.
Heat does not respect borders, and coordinated action within and across borders can better prepare countries for heat disasters. National meteorological services, health departments, local governments, labor authorities and emergency services must work together to ensure that heat warnings lead to clear, coordinated action on the ground.
For too long, extreme heat has been treated as a secondary climate risk. This is no longer valid. Heat now needs to be moved to the center of climate policy. The question is no longer whether South Africa can afford to act. Can afford it or not.
Jerome Amir Singh has received funding from the South African Academy of Sciences (ASSAf). ASSAf is a statutory body funded primarily through parliamentary grants allocated by the South African Government's Department of Science, Innovation and Technology.
Carradi Yale Wright receives funding from the South African Medical Research Council.
By Jerome Amir Singh, Full Professor in Clinical Public Health, Principal Investigator of the Scientific Advisory Group on Emergencies (SAGE), Honorary Research Fellow at Harvard College School of Law, University of KwaZulu-Natal, University of Toronto and
Carradi Yale Wright, Chief Specialist Scientist (Public Health), South African Medical Research Council