This guide presents a detailed methodology for integrating heat-related illness alerts into Electronic Health Record (EHR) systems, aimed at enhancing patient care during extreme heat events. It encompasses the evaluation of data quality, understanding EHR capabilities, and using tools like the HeatRisk Tool and Air Quality Index (AQI) to plan preventive measures. The guide also outlines patient identification techniques using the CHILL’D-Out Questionnaire to assess risks for conditions exacerbated by heat, such as asthma and cardiovascular disease. Additionally, it covers the importation of clinical heat value sets to manage high-risk patient registries, improve patient communication through API integration, and the step-by-step deployment process.