devoted to this task, and participate to the search and rescue, locating the casualties, extraction/extrication of the casualties and possibly perform first aid onsite; the medical chain has three functions: the first aid onsite, casualty lifting (scoop) and movement from the disaster location to the field hospital (called "advanced medical post", or PMA: poste médical avancé); triage and stabilising the casualties for the evacuation; the evacuation of the casualties to adapted care structures (hospitals). Distribution of the responsibilities The préfet of the département (or the préfet de police for Paris and its suburbs) is the director of rescue operations (DOS: directeur des opérations de secours). He starts the Novi plan; usually, the Novi plan is started by the firefighter or medical dispatch and then officialized by the préfet. The chief officer of the local fire and rescue department (SDIS: service départemental d'incendie et de secours) is the "commander of the rescue operations" (COS: commandant des opérations de secours). He is assisted by the "director of fire and rescue" (DSIS: directeur des secours incendie et sauvetage), and by the "director of medical rescue" (DSM: directeur des secours médicaux). The DSM is usually the chief-physician of the firefighters or the director of samu (French EMS). The main resources are the firefighters and Samu, but other organisations can contribute, such as the first aid associations (e.g. French Red Cross, volunteers of the civil protection/FNPC), who can contribute to the non-medical evacuations or deal with the relative emergencies, light wounded people and logistic for psychological aid (CUMP: cellule d'urgence médico-psychologique). The operational command The commander of rescue operation (COS) coordinates the rescue resources on site (public, private or associations). He must be easily spotted and has thus a yellow chasuble-like jacket on his clothes, with the inscription "Commandant les Opérations de Secours". He has an operational headquarters (PCO: poste de commandement opérationnel) near the site of the disaster. The OHQ has communications with all the resources and administrations, including the police. The director of fire and rescue (DSI) The director of fire and rescue (DSI) is a firefighter officer. He manages: the fighting against the initial disaster; the search-and-rescue operations; in the beginning, the scoop operations, before the medical chain is fully operational (increasing the resources) He has a yellow chasuble-like jacket with the inscription Directeur des Secours Incendie et Sauvetage. The director of medical rescue (DSM) The director of medical rescue (DSM) manages