To reduce emissions, adapt to climate change and protect citizens, cities need to integrate and implement appropriate measures in their master planning and other plans and policies to reduce the increase in city temperatures due to climate change and Urban Heat Island Effect (UHIE) and associated impacts. Chennai city has been selected under the UNEP-RMI India Urban Cooling Programme as a pilot city to carry out UHIE studies and frame an implementation plan to minimize the impacts of UHIE and rising cooling demand that will inform national methodologies and recommendations on best practices. The Chennai Metropolitan Area (CMA) is to undergo a seven-fold expansion to an area of 8,878 sq. km with the inclusion of new areas under its limits. The city of Chennai is witnessing rapid urbanization which causes massive pressures on energy consumption, and GHG emissions and increases the urban heat island effect (UHIE). This project under the Small-Scale Funding Agreement (SSFA) is being implemented by UNEP with the Tamil Nadu State Government, including the Chennai Metropolitan Development Authority (CMDA). The overarching objective of this project is to support CMDA to assess and integrate actions to mitigate and adapt to extreme heat and deliver sustainable cooling into various urban plans (including the New Area Development Plans for Satellite towns and the Third Master Plan 2026-2046), inform state and city level policy and implementation action and develop and test a methodology for assessing urban heat island for national replication.