The "Extreme Weather and Heat Response Modernization Act" mandates the Federal Emergency Management Agency (FEMA) Administrator to convene an advisory panel within six months of enactment. This panel, comprising diverse emergency management personnel, will review the process for determining incident periods for all hazards under the Stafford Act. Their review will specifically consider the effectiveness of incident periods for slow-onset, correlated non-contiguous, compound, and cascading disasters, aiming to improve FEMA's response capabilities. The bill authorizes FEMA to consider innovative preparedness and mitigation projects for extreme heat and cold events , such as stockpiling equipment and establishing emergency voucher programs. It also directs FEMA to provide guidance for the establishment and function of community cooling centers and resilience centers . Within one year, FEMA must issue comprehensive guidance on extreme temperature events, covering hazard mitigation eligibility and integration into various national preparedness and recovery frameworks. Additionally, the legislation requires FEMA to conduct a detailed study within one year on the impacts of extreme heat and cold. This study will examine effects on disadvantaged communities infrastructure health outcomes pets and livestock , and evaluate geographical differences and the effectiveness of emergency alerts. The Administrator must consult with stakeholders and federal agencies, ultimately recommending best practices for community education, first responder training, and incorporating these events into state and local emergency management plans.