Heat stress is causing unnecessary deaths, illness, economic losses, and reductions in infrastructure and urban service quality across cities worldwide. Assessing urban heat risks can help cities reduce these adverse impacts by providing an evidence base for planning, prioritizing, designing, and implementing policies and investments for heat resilience. This Technical Note aims to help readers plan a heat risk assessment and identify policies and investments to address the identified risks. Section 1 presents key considerations for planning a heat risk assessment. Section 2 presents methodologies for such an assessment. These are divided into methodologies to assess heat hazard (2.1), the likelihood and severity of its impacts on human health (2.2), and the city’s economy and infrastructure (2.3). Section 3 presents key policies and investments that can be undertaken in response to the urban heat challenge and discusses the roles of city- and national-level stakeholders in implementing them. The note concludes with a simplified catalogue of actions.