This dataset contains 2021 data on cities' climate change impacts on health and health systems, as reported by cities through the CDP-ICLEI Unified Reporting System in response to question 2.3a in the 2021 Cities questionnaire. View cities questionnaire guidance at https://www.cdp.net/en/guidance/guidance-for-cities. Please contact cities@cdp.net if you have any questions. This data is collected through the CDP-ICLEI Unified Reporting System. When using this data, please cite both organisations using the following wording: ‘This data was collected in partnership by CDP and ICLEI - Local Governments for Sustainability’. For further guidance on how to reference this data for use in external publications, please refer to the Open Data Portal Terms of Use available on the homepage.