The purpose of the challenge is to develop a prototype of a platform that brings together relevant, existing open global data and information to provide urban decision-makers with improved information and insight on understanding and managing risks from extreme heat in cities. The platform should generate insight on heat risks in urban settings combingin on hazard (heat), exposure and vulnerability data at a spatial scale that will allow cities to assess heat vulnerability from neighbourhood to neighbourhood, under current / future climatic conditions. Insights generated should be in plain language, with clear maps and data visualisations that allow decision-makers to understand the scale and nature of impacts in simple terms: location / number of people exposed/vulnerable, impact on illnesses, deaths, economic losses from lost days at work or school etc. The platform should use global datasets and the JRCs Global Human Settlement’s Layer urban centres dataset as its point of departure (for identifying all human settlements). The platform should leverage Earth Observation data to combine heat and exposure data to map and visulalise heat risks across and within cities. Reference datasets include: Temperature/heat: CHIRTS; ECOSTRESS Exposure (urban form): Global map of Local Climate Zones