What really happened in Chicago in July, 1995?

In July of 1995 an intense heat wave struck the U.S. mid-west, with heat indices rising to 119 degrees. In the wake of this heat came hundreds of deaths. How many were caused by the heat soon became a major political issue and scientific question. Epidemiology, which is often stated to be at the core of public health, had only infrequently been used in the past to address such questions. Those of us in the Chicago Department of Public Health were called upon to sort out crucial questions: How many really did die as a result of the heat? What were the risk factors for such deaths? What was the magnitude of associated morbidity? Could the heat wave have been predicted and the damage thus minimized? These questions and other like them had to be answered quickly and correctly in the midst of the epidemiologic laboratory that was Chicago during July, 1995. This presentation will summarize what we eventually discovered, what we were not able to discover, and how science and politics interacted in that complex environment.