The aim of this study was to examine whether the detection of pulmonary fat embolization is valid as a significant indicator of heat exposure in forensic autopsies. In 54 cases where there was no evidence of fracture, burn or pancreatitis, 25 cases (46.3%) showed pulmonary fat embolization, the degree of which was pathohistologically classified as slight in all cases. Among the 25 cases where the pulmonary fat embolization was detected, the individual had died under a high ambient temperature in 14 cases (56%). Based on logistic regression analysis, pulmonary fat embolization was found to be associated with a high ambient temperature, but not associated with coronary arteriosclerosis, fatty infiltration in the liver, severe infectious diseases, intracranial hemorrhage or the detection of methamphetamine in the blood. Further investigations are necessary before these findings can be applied in forensic autopsy cases; however, it is likely that the detection of pulmonary fat embolization is valuable as one of the diagnostic findings indicating antemortem heat exposure.