The Planning and Zoning Law requires the legislative body of a city or county to adopt a comprehensive, long-term general plan that includes various elements, including, among others, a safety element for the protection of the community from unreasonable risks associated with the effects of various geologic and seismic hazards, flooding, and wildland and urban fires. This bill would require a city or county, upon the next update of one or more of the elements included in the general plan on or after January 1, 2028, to review and update its safety element as necessary to address the hazard of extreme heat, as specified. The bill would authorize a city or county that has adopted an extreme heat action plan or other document that fulfills commensurate goals and objectives to use that information in the safety element, as specified, and, upon doing so, would require the city or county to summarize and incorporate into the safety element the other plan or document. The bill would also authorize a city or county to use or reference information in the Extreme Heat Action Plan and the State Hazard Mitigation Plan, as described, to comply with the above-described updating requirement. Existing law requires the planning agency to review and, if necessary, revise the safety element upon each revision of its housing element or local hazard mitigation plan, but not fewer than once every 8 years, to identify new information relating to flood and fire hazards and climate adaptation and resiliency strategies applicable to the city or county that was not available during the previous revision of the safety element. This bill would require the planning agency to also identify new information relating to extreme heat hazards applicable to the city or county that was not available during the previous revision of the safety element. The bill would include findings that changes proposed by this bill address a matter of statewide concern rather than a municipal affair and, therefore, apply to all cities, including charter cities. The California Constitution requires the state to reimburse local agencies and school districts for certain costs mandated by the state. Statutory provisions establish procedures for making that reimbursement. This bill would provide that no reimbursement is required by this act for a specified reason. This bill would provide that the changes proposed in Section 1 of this bill, amending Section 65302 of the Government Code, would not become operative if AB 1889 is enacted, and amends Section 65302 of the Government Code, as specified, in which case Section 2 of this bill, adding Section 65302.01 to the Government Code, would become operative.