Heat stress and sudden infant death syndrome incidence: a United States population epidemiologic study.

Objectives: To determine the role of heat stress in sudden infant death syndrome (SIDS) by examining the SIDS rates during periods of extreme environmental temperatures in a period when most infants were placed prone for sleep.

Design: A retrospective study of SIDS rates and mortality rates attributable to excessive environmental heat in relationship to climatologic temperature was performed. Data were collected for each of 454 counties in 4 states (Arkansas, Georgia, Kansas, and Missouri) from May 1 to September 30, 1980, and were then summed to yield the mortality rates for each 5 degrees F (2.