Heat transfer to compartment surfaces was measured in fully developed fire experiments. The experiments involved scaled compartments ranging from 1/8th to 3/8th with full-scale height of 2.54 m. Gas temperatures reached 1000°C, and total surface heat flux could reach 200 kW/m², with convection accounting for 25% of the total. A combination of thermopile heat flux gage, metal plate sensor, and gas and wall thermocouples was used to separate the convective and radiative components. The convective heat transfer coefficients were resolved experimentally. Convective heat transfer coefficient was correlated against temperature rise within the compartment for both flaming and after extinction phases.