The aim of this cross-sectional study is to investigate the impact of daily exposure to critical incidents in health and psychological well-being of the emergency ambulance personnel. The sample consisted of 250 firefighters from around the country, of both sexes. The results indicate that the ambulance personnel have on average some post-traumatic stress disorder symptoms (10% with symptoms compatible with a diagnosis of PTSD), significant peritraumatic symptoms, as well as psychological distress and health complaints. The ambulance personnel of the Algarve region have fewer symptoms associated with critical incidents. Correlational analyses indicated a negative significant association between symptoms and psychological well-being. PTSD is a mediator of the relationship between trauma exposure and dissociation on the health complaints and psychological well-being. This study presents a contribution to understanding the psychological consequences of daily exposure to traumatic incidents, and its impact on health and well-being of emergency ambulance personnel.