We describe a modified configuration of the temperature drift (TD) technique for recording infrared spectra that arise from vibrationally excited states. TD is a differential measurement that records decrements in IR absorptions due to modest increases in temperature. In particular, it permits identification of oscillators that are coupled to large amplitude, low frequency motions associated with transition structures, such as transitions to free rotations about single bonds that are hindered at ambient temperatures. Selected portions of the spectra of two species were recorded to demonstrate the feasibility of locating spectral features of critical, transition structures.