Emergency medical assistance is the first aid that is given to victims of accidents (casualties) or of the acute effects of diseases. The basis of emergency medical assistance is the "chain of rescue": this system is based on the collaboration of different actors. The most advanced cares can only be performed by physicians and surgeons with the appropriate environment (medical imaging, biochemistry analysis laboratory, emergency room, operating room), but the acute event often happens outside the hospital (prehospital cares): at home, in the street, at work, in a public building…