The relationship between communicable diseases and disasters merits special attention. This chapter does not address epidemics of emerging or reemerging diseases, chronic degradation of the environment, progressive climatic change, or health problems associated with famine and temporary settlements.In line with the definition of health adopted in the constitution of the World Health Organization (WHO), the chapter treats disasters as a health condition or risk, which, as any other "disease," should be the subject of epidemiological analysis, systematic control, and prevention, rather than merely as an emergency medicine or humanitarian matter.