The last decade was the warmest on record, and leading organisations on climate change indicate that warmer temperatures are not a potential threat but a surety. This report considers ways in which disaster risk reduction (DRR), climate change adaptation (CCA), and related scientific communities can rise to data challenges in order to provide policymakers with the evidence needed to set priorities and make decisions. Given the sizeable threat posed by extreme heat events, the report details the human impacts of heat waves, ranging from individual and community health to the built environment.