UCT project addresses heat risks in vulnerable communities

The University of Cape Town (UCT)-based research project, Heat Adaptation Benefits for Vulnerable groups In Africa (HABVIA), recently participated in the HeatNexus convening, highlighting its work on heat adaptation in vulnerable communities.

Hosted by the Institute of Development Studies (IDS), HeatNexus brings together nine Wellcome Trust-funded research projects focused on enhancing health outcomes through heat adaptation interventions in low- and middle-income countries (LMICs).

As climate change accelerates, extreme heat poses an increasing threat to human health, particularly in Africa, where heat-related health risks are compounded by socioeconomic vulnerabilities. The HABVIA project is addressing these risks through the evaluation of heat adaptation interventions in real-world settings, with a particular focus on vulnerable communities such as informal or low-income housing residents and manual labourers in South Africa and Ghana.

“Up to now, especially in South Africa, collaboration between the climate and health sciences has been rare. This project brings together rigorous non-communicable disease epidemiology and climate data analysis methods in an integrated design. Previous work on climate and health has largely been based on retrospective secondary data analysis using independent climate and health databases, which has meant interpreting the data harder to analyse,” says Professor Mark New, the co-principal investigator of the HABVIA project.

The roof painting initiative

One of HABVIA’s key interventions is its ongoing roof-painting project, conducted in four locations: Khayelitsha (Western Cape) and Mphego Village (Limpopo) in South Africa; and Ga-Mashie (Accra) and Nkwantakese (Kumasi) in Ghana. The project is testing the effectiveness of specialised reflective paint to reduce the housing structure’s internal temperature, with approximately 30 homes painted at each site. The internal temperatures of these houses are being compared to another 30 homes in each community, which were left unpainted as control houses. Co-creation is at the heart of HABVIA’s approach, ensuring that heat adaptation interventions are not only scientifically robust but also locally driven and sustainable. By actively involving communities in the design and implementation of solutions, the project fosters local ownership, skills development, and long-term resilience to extreme heat.

“Empowering low-income communities with heat-reflective roof paint is one step towards resilience and mitigating the effects of extreme heat. By collaborating with local communities on heat workshops and the roof-painting processes, we not only address immediate extreme heat challenges but also foster trust and sustainable change in tackling climate- and health-related issues. Moving ahead, we believe together we can turn the tide on extreme heat events – one roof at a time,” said Vuyisile Moyo, a postdoctoral research fellow at UCT working on HABVIA.

For example, in Khayelitsha, community participation was a central component of the intervention. Rather than relying on external contractors, local residents, as well as study participants were trained by the paint supplier to prepare and paint roofs, ensuring skills development and community ownership. This co-creation approach, made possible through HABVIA’s partnership with the Community Organisation Resource Centre (CORC) under Slum Dwellers International (SDI), reflects the project’s broader commitment to inclusive adaptation strategies.

Advancing climate resilience

With summer having been well under way and minimal rainfall, HABVIA’s data collection team was monitoring temperature variations in both painted and control homes to assess the impact of the intervention. By integrating climate, environmental, physiological, and mental health data, the study aimed to provide robust evidence on the effectiveness of passive cooling solutions in reducing heat-related health risks.

“As global temperatures increase, so does the risk for non-communicable diseases because the human body has to work harder to maintain normal bodily functioning, including a narrow body temperature range,” explained Professor Lara Dugas, the co-principal investigator of the HABVIA project. “Additionally, people who already have some sort of chronic disease, as well as the very young or elderly, are particularly at a heightened risk for heat-related injuries.”

The health data collected through a combination of objective physiological measurements, questionnaires, and biochemical assessments will provide a more accurate understanding of the relationship between temperature and risk factors for the development of non-communicable diseases.

During the hot season, 65 participants at each study site will undergo three non-consecutive rounds of health monitoring. Each monitoring period lasts a week and begins with an initial clinic visit, where participants complete anthropometric assessments, blood glucose tests, urinalysis, blood pressure measurements, and kidney function evaluations. Following this, they are fitted with wearable devices that track sleep, physical activity, and skin temperature while they go about their daily routines at home. During this period, temperature and humidity levels inside participants’ homes will also be monitored. A key outcome of the study is the ability to objectively measure these health indicators using wearable devices and directly link them to environmental exposures in home settings.

HABVIA as part of a global consortium

The HeatNexus convening provided an important platform for HABVIA to share its preliminary findings and engage with other research projects tackling heat adaptation challenges globally. As extreme heat is projected to cause up to 94 000 deaths annually between 2030 and 2050, and adaptation costs for developing countries are estimated to reach US$140–US$300 billion by 2030, scalable solutions such as reflective roof paint offer a promising avenue for protecting vulnerable populations.

HABVIA’s participation in HeatNexus reinforces UCT’s role in leading climate adaptation research and contributing to evidence-based solutions for communities facing the worst impacts of climate change. Through continued collaboration, knowledge exchange, and engagement with policy makers, HABVIA and its partners aim to drive meaningful change in how heat adaptation strategies are implemented in Africa and beyond.