As the climate crisis deepens, extreme-heat events are becoming more intense and frequent around the world. This has brought heat to the forefront of the conversations around climate change adaptation, and more and more city governments are concerned about the risks posed by extreme-heat events. Effectively communicating heat risk – especially to the most vulnerable communities – is essential for limiting the impact on people and their health. This report provides guidance on communication channels for reaching different heat-vulnerable groups, as well as city examples of heat communication best practices, and considerations for heat communication during the covid-19 pandemic. The report is based on discussions between seven north-american cities – Boston, Miami, New York City, Philadelphia, Phoenix, Toronto and Washington, DC – about best practices for communication responses to intense heat events.