Generally described, the present disclosure relates to measuring core body temperature through respiratory mechanisms. The disclosed techniques can use surface temperature, exhaled air, perfusion information, blood oxygen saturation, respiration rate, circadian rhythms, and the like to obtain an accurate reading of the body's core temperature. Example devices are disclosed for obtaining core temperature from exhaled air and useful mechanisms for presenting this information to a user are also disclosed, including user interfaces and alarm mechanisms. Stereo thermometry methods may also be used to estimate core body temperature. This information can be used to track conditions of a subject, including fever status and comfortability, to ensure full consideration of a subject's well-being.
