Heat Indicators for Global Health (HIGH Horizons)

5 September 2022

HIGH Horizons


Aims and objectives

The HIGH Horizons project aims to identify cost-effective, integrated adaptation-mitigation interventions to alleviate heat impacts on health workers, and to reduce carbon emissions associated with health care. The project also aims to implement a system for monitoring the global-, national- and district-level health impacts of extreme heat among pregnant women and infants in Europe and sub-Saharan Africa; and to develop an Early Warning System using a smartphone app to provide individualized heat stress warnings, targeting pregnant women, infants and health workers.


The built environment in many parts of Africa is poorly suited to extreme heat.Integrated, complementary adaptation and mitigation interventions in health facilities could have a major impact, including sizable health co-benefits. Many interventions, especially natural solutions such as greening that help to adapt to extreme heat also reduce carbon emissions. Greening has many environmental and health co-benefits, including noise reduction, improvements in social wellbeing and amelioration of the mental health impacts of extreme heat. Moreover, implementing a package of interventions offers potential cost-benefits of scale. Extreme heat affects the wellbeing, health, and work performance of health workers, including through heat-related fatigue, absenteeism, and changes in mood. Monitoring heat impacts is critical for tracking heat-related conditions and identifying effective measures.


HIGH Horizons consists of two sub-studies. Firstly we systematically design and evaluate a combined adaptation-mitigation package of interventions for health facilities in Tshwane, South Africa and in Kilifi, a rural area in Coast Province Kenya. A range of modifications to health facilities will be assessed using thermal, carbon emissions and cost-effectiveness modelling, allowing us to select a package of interventions that reduce heat exposure for health workers and limit carbon emissions. The modelling tools have previously been applied in other parts of Africa. A range of heat adaptation interventions will be considered, centring around passive cooling systems, including minor modifications to buildings, such as shading and enhanced natural ventilation. Electric and hand-held fans with light water spraying offer low-cost, scalable alternatives to air-conditioning. Though air conditioning has major drawbacks, we will assess the costs and benefits of using air conditioning in a few designated ‘cool spaces’ within a health facility. Solar powered cooling systems will be employed wherever possible.

Mitigation interventions may include alternatives to grid electricity (such as solar panels), reduced use of harmful refrigerants (e.g. replacement of air-conditioning split panels); or increased off-setting measures (e.g. planting of trees around the facility) Health worker wellbeing, health, productivity and quality of care will be measured, including through time-motion studies, together with facility indoor temperatures and emissions, and compared before and after the intervention.Indoor temperature and air pollution levels will be monitored throughout. In the second sub-project, heat impacts and data science predictive modelling will be done to document a wide range of heat-health impacts in pregnant and postpartum women and infants. Analysis will draw on routinely collected health records in health facilities in Kenya, Tanzania and South Africa, and from population registers in Sweden and Lazio, Italy. We will select cut-off threshold levels of heat for an Early Warning System for pregnant and postpartum women, infants and health workers, each group separated into several sub-groups based on risk profiles. The risk profiles will be informed by ongoing time-series and machine learning analyses. The smartphone app used in this study will be adapted from ClimApp that was developed and applied in an another EU-funded project. The ongoing analyses provide data for monitoring systems and indicators.

Timelines and anticipated impact

Over four years the project team will test the first integrated adaptation-mitigation project within health facilities in Africa. Additionally, the project is the first worldwide to systematically co-design Early Warning Systems based on personalised heat thresholds determined from heat-health time series analyses, which are updated as new data become available.

Other project partners

Centre for Sexual Health and HIV/AIDS Research Zimbabwe (CeSHHAR Zimbabwe)
Health Organisation (WHO), Switzerland; London School of Hygiene and Tropical
Medicine, UK; Lunds University, Sweden; Karolinska University,
Sweden; Azienda Sanitaria Locale Roma, Italy; Denmark Technical
University, Denmark; and the University of Graz, Austria.

Project funder

European Union, Horizon programme

Project status:

Start-up early 2022

Role of Wits RHI

Wits RHI is the lead on research activities in South Africa (MF Cher

Latest Update: 09 March 2022

For more about HIGH Horizon please email:

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