The second half of the 20th century has brought about major changes in paramedic training, work, and vehicles. In Switzerland, an utopian narrative remains strongly linked to the fast process of professionalization, often formulated as 'mutation', from the 1950s to present days. This paper argues that there is however a lack of historical knowledge about modern, civil, and motorized forms of emergency medical services. Starting with a case study in French-speaking part of Switzerland, we examine the process, between 1955 and 1964, which leads to the creation of the first official and subsidized ambulance service in Switzerland. To that purpose, we analyze written material and we demonstrate how a "need for emergency services" discourse - pertaining first to the police work, then to the paramedic work - was developed and disseminated. Also present within the documents and analyzed in our paper is a process for transforming the paramedic status from a carrier or picker, into an out-of-hospital healthcare professional.