To prioritize the most common effects of a disaster, HCPs must decide in advance what is needed and how, when, and whom to provide the necessary support to deal with the posteffects of a disaster. During the rescue mission, the primary public health concern is clean drinking water, food, shelter, and medical care. Medical care is critical especially in areas where little or no medical care exists. Natural disasters do not necessarily cause an increase in infectious disease outbreaks. However, contaminated water and food supplies as well as the lack of shelter and medical care may have a secondary effect of worsening illnesses that already exists in the affected region. Appropriate preparation in the form of preplanning for immunizations as well as education about other forms of protection, such as appropriate apparel and water decontamination, promotes a safer environment for first responders and survivors. The continued need for postdisaster health monitoring for HCPs is imperative. The effects of a disaster last a long time; therefore there is an ongoing need to focus on the physical and environmental effects, including surveying and monitoring for infectious water or insect-transmitted diseases; restoring normal primary health services, water systems, transportation, housing, and employment; and continuing to assist the community's recovery after the immediate crisis has subsided.