Magic Lens/Shutterstock 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 storms, extreme heat rarely leaves dramatic images of destruction. But it builds without relief, putting strain on people’s bodies, homes and health systems.
In many cases, the danger is intensified when temperatures stay high overnight, leaving little chance to recover.
Read more: Heat with no end: climate model sets out an unbearable future for parts of Africa
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 across southern Africa working on climate, health and policy.
We recently conducted a regional consensus study for the Academy of Science of South Africa (ASSAf) to assess how extreme heat affects health and daily life across the region. Our aim was to determine what practical steps are needed to reduce the harm caused by extreme heat.
We worked with a team of independent experts from across disciplines to review scientific evidence, regional data and policies, and to develop a shared, evidence-based view of how extreme heat is affecting the region.
Our study was unique because it brought together evidence from across health, labour, food systems and infrastructure to show how heat affects everyday life, analysing heat not just as a weather event, but as a system-wide risk.
Read more: Heat extremes in southern Africa might continue even if net-zero emissions are achieved
We found that extreme heat is already a defining climate and health threat in southern Africa.
One of the biggest mistakes in public discussion is to treat heat as simply a weather event. 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, respiratory and renal (kidney) disease.
Heat needs to be treated as a major public health and development priority across the Southern African Development Community.
The Southern African Development Community has 16 member states, home to more than 400 million people. Yet collectively, these countries contribute less than 1.3% of global greenhouse gas emissions.
Despite this, southern Africa is already heating up fast. Average surface temperatures across the region have risen by 1.0-1.5°C since 1961. A further 4.5-5°C increase is projected by 2050 under high-emission scenarios (where fossil fuel companies continue to pollute at the same rate as they are now).
Read more: Climate change has doubled the world’s heatwaves: how Africa is affected
In our report, we describe extreme heat as an “integrator hazard” (a multiplier). This means it is not only one risk but makes existing problems worse all at once.
For example, extreme heat can reduce crop yields and nutrient quality, increase water stress, worsen air quality through dust and wildfire smoke, and disrupt livelihoods that depend on safe outdoor work – all at the same time. That is what makes heat so dangerous.
Read more: South African study finds 4 low-income communities can’t cope with global warming: what needs to change
It can also make already hot environments – especially informal settlements with limited shade, ventilation or cooling – far more dangerous. Extreme heat can place added strain on electricity systems. This increases the risk of power outages just when cooling, water supply and health services are most needed.
