Motor vehicle-related child hyperthermia fatalities (MVRCHF) have risen slightly in the past decade, but little research has been done investigating the circumstances surrounding MVRCHF. In order to address gaps in our understanding, the current study describes MVRCHF circumstances among children <1-14 years of age in the United States from 1999 to 2007. Three sources were used to identify child hyperthermia death cases in the United States from 1999 to 2007: the Centers for Disease Control and Prevention's Compressed Mortality File (1999-2004), the Golden Gate Weather Service's public MVRCHF database (2003-Present), and an independent internet search. Data about the victim's characteristics and the circumstances surrounding the death were extracted. From 1999 to 2007, 231 MVRCHF were identified. Children were left unattended in >80% of cases, 25% of victims were playing at the time of death, and 60% were male. On average, the core body temperature was 107.2 degrees F after being left inside the vehicle for an average of 4.6 h. The largest number of deaths occurred in the South, followed by the West, Midwest, and Northeast. Parents were found to be accountable for 2/3 of the hyperthermia deaths. The geographic distribution of incidence may be attributable to two major influences: (1) regional climate differences; and (2) population characteristics. The accountability of parents for MVRCHF is likely due to the exposure-risk concept, in which the situation/circumstances increase the injury probability.