The Preventing Health Emergencies And Temperature-related Illness and Deaths Act of 2025, or the Preventing HEAT Illness and Deaths Act of 2025, seeks to mitigate the significant health risks posed by extreme heat across the United States. Recognizing extreme heat as a leading cause of weather-related deaths and a critical environmental justice issue, the bill establishes a comprehensive federal framework to improve preparedness, planning, and response to heat events. A central component of this framework is the establishment of the National Integrated Heat Health Information System (NIHHIS) within the National Oceanic and Atmospheric Administration (NOAA). NIHHIS is tasked with improving the delivery of heat-related data, forecasts, and warnings, developing science-based solutions for heat resilience, and providing technical assistance through centers of excellence. The System's Director will foster robust relationships with federal and non-federal partners, including emergency management, public health, and community representatives, to identify needs, conduct research, and deliver actionable information. Complementing NIHHIS, the bill creates the National Integrated Heat Health Information System Interagency Committee , also housed within NOAA. This Committee will coordinate, plan, and direct activities across numerous federal agencies, including Commerce, Health and Human Services, Interior, EPA, and FEMA, to ensure a unified federal approach to reducing heat-health risks. Its broad membership includes representatives with expertise in weather, climate, health impacts, environmental justice, and urban planning. The Committee's responsibilities include developing a 5-year strategic plan to improve coordination of federal capacity and capabilities. This plan will outline strategies for enhancing data collection and management, fostering research and innovative solutions, and establishing mechanisms for financing heat planning, preparedness, and response. The Committee is also mandated to consult with regional, state, local, and Tribal governments, as well as research institutions and non-governmental organizations. Furthermore, the bill requires a study on extreme heat information and response , to be conducted by the National Academies of Sciences, Engineering, and Medicine. This study will identify policy and research gaps, particularly concerning vulnerable populations, data deficiencies (e.g., lack of air conditioning in public facilities, demographic breakdown of affected individuals), and the effectiveness of existing heat-health tools. It will also provide recommendations for addressing these gaps and promoting community resilience and environmental justice. To support on-the-ground efforts, the legislation establishes a Community Heat Resilience Program to provide financial assistance to eligible entities. This assistance, in the form of prizes, contracts, grants, or cooperative agreements, will fund projects such as sustainable heat reduction solutions (e.g., cool roofs, urban forestry), training programs, and initiatives to expand public awareness and establish local heat action plans. Eligible entities include nonprofit organizations, states, Indian Tribes, local governments, and academic institutions. A key priority for this financial assistance is to benefit historically disadvantaged communities and communities with significant heat disparities , with not less than 40 percent of funds allocated to projects in communities with environmental justice concerns or low-income communities. The bill authorizes significant appropriations for NIHHIS, the Interagency Committee, the study, and the financial assistance programs from fiscal years 2026 through 2030, totaling $100 million for the system and committee, $1.5 million for the study, and $100 million for financial assistance.