HEAT (Heat Emergency Awareness and Treatment Bundle) Trial

What did the study set out to achieve?

The purpose of this study was to develop and test a set of interventions to reduce the impact of extreme heat on urban low-income populations. There were three main objectives:

1. To develop evidence based care strategies for management of people with exposure to extreme heat (EH) in both households and emergency departments in low income settings such as Pakistan;
2. To implement Heat Emergency Education and Training (HEAT) bundle in Karachi and measure its impact on a composite outcome comprising of emergency department admissions, hospital admissions and all-cause mortality
3. To determine the impact of HEAT implementation on the knowledge and care practices in households and emergency departments.

The study filled several critical gaps in research by carrying out the first randomised controlled trial comprised of a set of customised community- and hospital-based interventions in a low-income urban population, with inclusion of a control group of similar socio-economic status in the same city. The study also included standardised assessment for categorising causes of heat related morbidity and mortality, and attempted to control for some of the important external confounders by collecting data before the intervention was carried out. In order to align the research intervention with what could be done in real life, the study team relied on indigenous community health mobilisers and the infrastructure present in local healthcare facilities.

What were the key findings?

• The community intervention-exposed clusters had fewer heat-related outcomes (death, hospital visit and admission). The ventilation of houses was associated with fewer outcomes.
• Communities viewed engagement of community health workers and other nongovernmental organizations in a positive light and trusted the support received.
• However, changes in community knowledge, attitude and practices about heat-related illnesses showed mixed results. While knowledge and understanding were improved, this did not necessarily lead to changed behavior or care-seeking.
• Emergency physicians significantly improved their knowledge of diagnosis and management of heat-related illnesses after the intervention.

What does this mean for policymakers and practitioners?

• Educate populations in methods to protect themselves during extreme heat events, such as increasing water intake, avoiding outdoor activities during peak hours, eating light foods, taking rest in the shade, and paying attention to infants, young children, elderly and those with other illnesses.
• Strengthen and equip health care systems to manage the health impacts of extreme temperatures.
• Front line health care providers in emergency settings should consider the diagnosis of heat related illness and be aware of its management protocol when interacting with individuals who present with elevated temperatures, nausea and vomiting, unconsciousness, muscle cramping, weakness and altered mental status with positive heat exposure.
• The HEAT manual can be culturally attuned and translated to suit the needs of other regions in Pakistan as well as other low resource settings to provide physicians and nurses with the opportunity to educate themselves about heat related illnesses.
• Health care institutions and governments at various levels should work together to accelerate the development of heat management systems, given extreme temperature conditions are predicted to rise with climate change.