Estimating the incidence of heat-related deaths among immigrants in Pima County, Arizona.

Widespread media reports have described an increase in heat-related deaths among illegal immigrant border crossers in Southern Arizona in recent years. We conducted a retrospective case series review of heat-related deaths reported by a large border county medical examiner office in an attempt to estimate the occurrence and distribution of these deaths for the years 1998-2003. United States Border Patrol apprehension data were also collected and used in the analysis to estimate the size of the population of border crossers. An increase in the total heat-related deaths has occurred since 1999 in Pima County Arizona and has continued to date. Precise estimates of rates are not possible but appear to have increased as well. Implications for understanding the complexity of researching this public health issue including the definition of cases and population at risk are discussed.