Public health - basic concepts and significance. Concept of crisis and public health significance Characterization of a crisis and emergiences and their relevance to public health Types of extraordinary events, analysis. Preparing for a crisis event. Response to crisis and emergency situation, population and individual approach. Water supply on extraordinary occasions. Nutrition on extraordinary occasions. Accommodation in extraordinary circumstances Vulnerable groups and public health. Community activities in emergency and crisis situations Health system and organization in crisis and emergencies. Communication in crisis and emergencies. Prevention of crisis situations. Post-crisis rehabilitation. The importance of knowledge of demographic indicators for prevention, crisis and rehabilitation.