Executive Summary

This report synthesises current evidence on heat-related health risks and policy responses across G20 and BRICS countries, highlighting the growing urgency of extreme heat as a major climate-driven public health threat. Global temperatures have now consistently exceeded 1.5°C above pre-industrial levels, with recent years ranking as the hottest on record. As a result, heatwaves are becoming more frequent, prolonged, and intense, contributing to an estimated hundreds of thousands of deaths annually and widespread impacts on health systems, labour productivity, and infrastructure.

Across G20 and BRICS countries, projections indicate substantial increases in heatwave frequency and duration by mid-century, particularly in Global South countries. Heat exposure is associated with a wide range of adverse health outcomes, including heatstroke, cardiovascular and respiratory complications, exacerbation of chronic diseases, and mental health impacts. Indirect effects include increased transmission of infectious diseases, reduced labour productivity, and strain on healthcare systems. Vulnerability is unevenly distributed, with heightened risks among older adults, children, pregnant women, individuals with chronic illnesses, outdoor and informal workers, and populations living in low-income or poorly serviced environments.

View the complete Heat-Related Health Risks and Responses of G20 and BRICS Countries Report