Summary The primary task of emergency medical technician-paramedics (EMT-P) is to provide prehospital emergency care while ensuring safe transportation of the patient to a hospital. Fundamentally, their objective is to reduce patient mortality and morbidity as much as possible by minimizing response time. Numerous studies throughout the world, including in Québec, show that EMT-Ps have a higher level of employment injuries and take retirement earlier than other workers, including those in the health system. As they get older, many EMT-Ps leave their jobs for another profession with less demanding tasks. Little attention has been paid to what actually takes place on the job and the currently used measurements of exposure to risk factors have often been insufficient. The objective of this project is to describe EMT-Ps’ work context and to quantify their exposure to risk factors for musculoskeletal disorders. The observation of 101 EMT-Ps working in the regions of Montréal and Québec City over 175 work shifts made it possible to document the tasks and the many different situations that they face every day. The impact of the various work determinants was characterized and those that were adverse, i.e., those that could provoke an imbalance between their well-being and health and work expectations, were identified. Confronted with ever-changing situations on the job, EMT-Ps make decisions based on the information available to them, but many aspects of the work environment cannot be predicted until their first contact with the patient. Work situations requiring an evacuation by emergency transport represented less than 10% of prehospital interventions. The difficulties faced by EMT-Ps stem from the patients’ unstable health status, because it dictates which actions must be taken, such as choice of treatment protocol and priority of evacuation. This factor explains the haste exhibited by EMT-Ps, especially in emergency situations, and is partially responsible for the high workload and physical efforts of the two-person team. The care provided to patients, guided by well-defined protocols, is the task that comes with the highest risk of back injury, based on postural indexes. The tasks involved in moving patients, especially when they must be lifted and carried, are also among the most difficult. Overall, EMT-Ps who are female, have several years of seniority, or who are obese adopt safer work postures than their coworkers. When carrying out emergency evacuations of patients, female EMT-Ps felt they were very pressed for time, which was expressed by a perception that they were working much harder than the men. However, with respect to physical effort, the task duration and fatigue levels were similar between them. Technicians with more than 15 years of experience perceive non-emergency work situations differently. They feel that the physical effort, workload and time pressure are greater than what is perceived by technicians with less seniority, although the difference was relatively small. The EMT-Ps assigned to providing care to the patient are exposed to much higher risk factors than the other members of their team. This finding was associated with the practice of alternating roles in a work shift after each intervention that required emergency transportation. Waiting periods generally follow each prehospital intervention, which provides the workers with some recovery time. The situations that demand maximum cardiorespiratory aptitude (VO2max) are not very frequent. Therefore, the limited aerobic capacity of some EMT-Ps, observed especially among those who are obese, does not represent a major limitation in their work, although it is undesirable. Up to a certain point, the negative effects of a high workload during situations that require the emergency transportation of a patient appear to be offset somewhat by the decisional latitude of the EMT-Ps. However, it raises the question of whether compromises are made with respect to the quality of service, rapidity and their safety. The adage “each minute counts,” in the prehospital environment illustrates the perceived need to rush and the associated high temporal demand, while “all the minutes count” in a non-emergency situation, to ensure a quality of service that will optimize the well-being of users. This large-scale project painted a clear portrait of the profession of EMT-P: the demands of the job make it an at-risk occupation with its share of difficulties. The information collected will enhance the training curricula of future EMT-Ps and will contribute to preventing health problems that affect far too many prehospital emergency care workers.