Firefighter protective clothing (FPC) provides barrier protection from hazardous materials. Two of the important performance factors tested for FPC are total heat loss (THL) and thermal protective performance (TPP). The present study evaluated the relationship between THL and TPP, and tested its subsequent influence on burn injury prediction via the flame-engulfment manikin test, using three FPC samples from the United States, Europe, and South Korea. The study results showed an inverse relationship between THL and TPP (r=-.949, p<.001). Predicted total area of second and third degree burn injury was 7.2±1.6, 19.7±4.1, and 5.0±1.0% for the United States, European, and South Korean FPC, respectively, which was significantly explained by both THL and TPP (F=34.630, p=0.001, R2=.920). The flame manikin test results showed that affected burn injury areas are not uniform over the body, but more frequent on the head and limbs.