To save the life of patients with critical illness, immediate medical intervention and rapid emergency medical evacuation are important; this is the basic concept of "prehospital emergency medical care." Doctor cars are designated as emergency vehicles, and helicopter emergency medical services(HEMS)send doctors and nurses to emergency situations to quickly start the initial treatment and transport patients to medical institutions. In Japan, 56 medical helicopters have been deployed nationwide across 47 prefectures. According to a registry report in Japan, HEMS transport for cerebral ischemic stroke resulted in a higher rate of interventional treatment compared to that provided by ambulance transport and significantly affected favorable outcomes 1 month later. A questionnaire survey assessing doctor cars in Japan revealed disparities in the operation of doctor cars across facilities. The prehospital stroke scale effectively transports patients to stroke centers for endovascular thrombectomy for large-vessel occlusion. To demonstrate the usefulness of doctor cars and HEMS, the medical system should be tailored to the characteristics of the region of operation.