A study was conducted to compare the two methods, Henriques Burn Integral and Stoll criteria, in thermal protective performance evaluation on firefighter clothing composites exposed to various thermal hazards. The thermal hazards that the firefighter may encounter during fire fighting are low level thermal radiation and high intensity flashover fire. With the simulation of these thermal hazards in the lab, the heat flux behind exposed clothing composites are characterized with flux rise rate and peak heat flux. Comparisons were performed on the prediction differences of clothing system made using Henriques Burn integral and Stoll criteria under different conditions. The study demonstrated that in some cases less difference is predicted by the two methods, while in other cases a significant difference is observed. Several recommendations were made for the qualitative prediction of garment and fabric thermal protective performance under different situations.