Four real-scale experiments were conducted by the National Institute of Standards and Technology to measure the temperatures above and below a wood floor assembly exposed to fire conditions from below. The objectives of the experiments were: 1) to examine the heat transfer through a wood floor assembly and 2) to examine the ability of a thermal imager to determine the potential severity of the fire beneath the floor assembly and the ability to provide a sense of the structural integrity of the floor assembly in order to provide improved situational awareness.