Disasters are a major public health issue because they affect large groups of people and have short-, medium-, and long-term physical, psychological, and social consequences. In a major disaster situation (whether natural or man-made), two distinct phases can be identified, both of which are important: - the emergency phase, during which standard management measures include evacuation, shelter, and restrictions on water or certain food supplies; - the post-disaster phase, during which management issues related to the disaster’s consequences often persist (pollution, property damage, etc.) and additional problems arise (social repercussions, psychological distress, and other long-term health risks). (R.A.)