To better understand the extent of how the air temperature and mean radiant temperature may vary both spatially and temporally in a radiantly heated space, we conducted a seven-day experiment in the architectural laboratory at School of Architecture, Princeton University. The primary intent of this paper was to decouple the measurement of the air temperature and mean radiant temperature. We collected a large dataset that shows temporal and spatial variations. To do so, we used non-contact infrared thermometer to measure the surface temperatures of the surrounding surfaces inside the laboratory. The geometry of the laboratory is simplified into a box, the corresponding view factor from every point within the box can be calculated towards each internal surface. These view factors are then combined with the measured surface temperatures to produce mean radiant temperatures. This spatial mean radiant temperature distribution was then compared with the air temperature distribution measured by the air temperature sensors suspended from the ceiling of the laboratory. We believe making these data available will help future researchers working on similar problems to develop protocols than the state-of-the-art measurement techniques observed among different thermal comfort or radiant heat transfer research.