The Extreme Heat Emergency Act of 2025 proposes to amend the Robert T. Stafford Disaster Relief and Emergency Assistance Act, which governs federal disaster response. Specifically, it expands the definition of a "major disaster" to explicitly include extreme temperature events, such as severe heatwaves or cold snaps. This amendment would enable the President to declare extreme temperature events as major disasters, thereby making federal assistance available to affected states and localities. A crucial provision of the bill is that no additional funds are authorized for its implementation, meaning any federal aid for extreme temperature disasters would be drawn from existing appropriations under the Stafford Act.