Despite the climate crisis driving more bouts of devastating heat, too much of the world remains poorly prepared. Nuzhat Nueary introduces new Oxfam/FCDO research that looks at the links between extreme heat and water scarcity and highlights glaring gaps in humanitarian response.
Why is extreme heat not seen as an urgent priority for global action in the same way as other disasters such as floods? Heat claims many lives across the world. This year alone, for instance, at least 15 people died across different parts of Bangladesh directly from heatstroke. And beyond the immediate loss of life is the broad damage caused by extreme heat, as water rapidly evaporates, devastating food production, agriculture and livelihoods. And of course the risk is increasing as experts link the rise in heatwaves such as the recent ones in Europe directly to climate change.
Alarming as the impact of heat on people’s lives can be and despite the growing risks, it remains a low priority in terms of action, adaptation, resilience and disaster planning in many countries of the Global South. This contrasts with the Global North, where heat is increasingly being integrated into planning and policy.
To explore this further in a humanitarian context, Oxfam and the FCDO undertook a research study to understand the impacts of extreme heat on rural and displacement-affected communities in South Sudan and Bangladesh, focusing on water scarcity. The research, conducted in Gerbana and Renk in South Sudan, and Satkhira and Cox’s Bazar in Bangladesh, examines four key questions:
- What are the impacts of extreme heat on communities, especially on nutrition, food security, livelihoods, health, mobility and protection?
- What is the relationship between extreme heat and water access, availability, and quality, and how do these water-related challenges influence overall well-being?
- What coping and adaptation mechanisms are used by community groups, and how effective are these?
- To what extent does humanitarian programming integrate extreme heat considerations and where are the gaps in response?
Here, we share key takeaways, which you can read about in detail in our published report on heatwaves.
1. Extreme heat has big impacts on the access and availability of water – but these vary with context
It was clear from our research that, in both South Sudan and Bangladesh, extreme heat significantly damages water availability, access, and quality but this played out in distinct ways in different places including the dry, arid context in South Sudan; the very humid conditions in Bangladesh; and the context of displacement camps.
The coastal areas of Satkhira, Bangladesh are highly vulnerable to saltwater intrusion. Extreme heat intensifies freshwater shortages and ongoing agricultural challenges. Despite being surrounded by water and equipped with deep tubewells, water is often contaminated with salt, iron, and arsenic: salinity further increases during extreme heat.
In displacement settings in both Renk and Cox’s Bazar, increasing heat has resulted in groundwater depletion. The growth in refugee and returnee populations and the lack of adequate sanitation infrastructure are also critical drivers of disease. Heatwaves exacerbate this risk of disease as pathogens spread more easily in high temperatures.
In Cox’s Bazar, the rise in population has overwhelmed the water supply system, making it difficult to meet growing demand. Additionally, forest degradation in the region has undermined efforts to restore local water sources. In contrast, in the dryland region of Renk in South Sudan, local water sources, such as hafirs (rainwater harvesting ponds), have been severely affected by extreme heat and declining water quality. What is clear is that across contexts, in periods of extreme heat, water rapidly evaporates, exacerbating scarcity in multiple ways— which ultimately affects food production, agriculture, and other key livelihoods.
2. Extreme heat has more severe impacts on particular groups
Our research covered a wide range of landscapes and communities from diverse backgrounds. Some villages were isolated from the mainland, others were in cramped environments such as the Rohingya camps, and some were situated in border regions like Renk in South Sudan.
All experienced heat in different ways. For instance, in the mountainous regions of Teknaf, Cox’s Bazar, communities face acute water crises as freshwater becomes scarce. In Cox’s Bazar, the impact of heatwaves is particularly severe on women, as cultural norms restrict Rohingya women from leaving their homes. As the shelters in which displaced Rohingya communities live are made of tarpaulin, they become unbearably hot. Outdoor workers face specific challenges in scorching sun. Many reported reduced wages as they were unable to work full hours due to the extreme heat. Children, pregnant women, and animals were also found to be especially vulnerable, facing higher risks of waterborne diseases such as diarrhea as the heat accelerates their spread. This is particularly alarming in rural areas with poor sanitation.
3. Communities are already adapting to heat – and they need to be supported
Our research revealed how communities are leading the way in adapting to extreme heat themselves, often unseen and unsupported by authorities and international organisations.
We found communities in Bangladesh and South Sudan adopting diverse strategies from water management to housing modifications and mobility. In Bangladesh, people collect and purify rainwater, use communal water sources, cool homes with palm leaf roofs, thick curtains, and water-sprayed walls, and adjust routines to avoid peak heat.
In South Sudan, adaptations include covering jerricans to keep water cool, designing thermally comfortable homes, and using fans or air conditioning depending on income. Poorer households plant trees or build makeshift shelters (rakuba), while children are often wrapped in wet clothes for heat relief.
Mobility is another key adaptation strategy found among people in Renk, where families move to areas with better water access, or women and children temporarily stay with their relatives. However, these adaptation efforts are not formally documented or supported. They need further investigation and support – and need to be integrated into heat action planning.
4. There are major gaps in policy and practice – and early warning systems
There is a lack of policy and practical action around extreme heat in humanitarian response, though Bangladesh shows more progress in this area than South Sudan.
Organizations such as Bangladesh Red Crescent Society, IFRC, WFP, and Save the Children have begun engaging on heat-related issues in Bangladesh. However, in South Sudan, heatwaves only seem to get attention during school closures, and do not seem to feature in humanitarian preparation and planning. A major barrier across contexts to effective heat response is the lack of reliable early warning systems and forecasting capacity, particularly in rural and remote areas. Although anticipatory action and early warning are discussed in coordination forums like Clusters and Working Groups, implementation is limited.
How can we start to transform response to extreme heat?
Our report draws on research in both countries to make recommendations for humanitarian organisations and policymakers, including:
- It is critical to build up effective long-term heat action planning.
- Such planning should put at its heart local and impacted communities’ concerns. Community innovations and adaptation must be integrated into both emergency response plans and protracted crisis management, including climate policies.
- Humanitarian actors and governments must improve weather forecasting at remote and rural areas to create proper heat warning systems.
- The government, along with humanitarian agencies, should provide training to local health workers and medical personnel, and integrate heatwave awareness into public health promotion.
What is clear from our research is that extreme heat must take its place as a critical part of humanitarian action, alongside other natural disasters such floods. Both humanitarian agencies and governments need urgently to make heat a priority, plan for it and take action. Without such action, especially in a warming climate, too many communities will face surging death rates – and a growing water crisis.
Author
Read the full report by Padmini Iyer and Nuzhat Nueary, (2025) Extreme Heat in Humanitarian Contexts: Research from Bangladesh and South Sudan. Oxfam International.