Heat-related illnesses and deaths--Missouri, 1998, and United States, 1979-1996.

Although heat-related illness and death are readily preventable, exposure to extremely high temperatures caused an annual average of 381 deaths in the United States during 1979-1996. Basic behavioral and environmental precautions are essential to preventing adverse health outcomes associated with sustained periods of hot weather (daytime heat index of > or = 105 F [> or = 40.6 C] and a nighttime minimum temperature of 80 F [26.7 C] persisting for at least 48 hours). This report describes four heat-related deaths that occurred in Missouri during 1998, summarizes heat-related deaths in the United States during 1979-1996, describes risk factors associated with heat-related illness and death, especially in susceptible populations (young and elderly, chronically ill, and disabled persons), and recommends preventive measures.