The purpose of this project is to develop an evidence-based public health intervention to reduce heat-related maternal and fetal health complications as extreme heat events increase due to climate change. A growing body of epidemiologic research links prenatal heat exposure to adverse pregnancy outcomes, including preterm birth, low birth weight, stillbirth, hypertensive disorders of pregnancy, and maternal hospitalization. In the United States, around 1 in 10 infants are born preterm, and research suggests that exposure to extreme heat during pregnancy can increase the risk of these complications, with extreme heat event exposure increasing the risk of preterm birth by 2-5%. Using the PERIE framework, this project defines the scope and burden of heat-related pregnancy complications and then examines key contributing factors, which include dehydration, reduced blood flow to the placenta that can limit oxygen and nutrients to the fetus, inflammatory stress responses, inadequate housing conditions, occupational heat exposure, and limited access to cooling resources. Based on this analysis, the project proposes a multilevel intervention integrating prenatal heat-risk counseling, targeted heat alert systems for pregnant women, strengthened clinical guidance during extreme heat events, and partnerships with local health departments to incorporate pregnancy-specific protections into municipal heat event action plans. Program evaluation would assess changes in preterm birth and other adverse birth outcomes during extreme heat periods compared with baseline conditions, along with measures of health care utilization and patient awareness of protective behaviors. Addressing heat exposure during pregnancy represents an achievable strategy to reduce preventable maternal and fetal morbidity and mortality and strengthen climate change adaptation in public health.