The present invention includes an apparatus and method for measuring hysteretic heating or stress of one or more bearings of a craft comprising: one or more non-contact temperature sensors attached to the craft and directed toward the one or more bearings; and a computer connected to the one or more non-contact temperature sensors that measure the temperature, the stress, or both of the one or more bearings before, during, or after operation of the craft, wherein the one or more non-contact temperature sensors measure a change in temperature in the one or more bearings to monitor for heating or stress of the bearings.