There have been substantial advances in multiple wavelength infrared imaging systems that can measure emissivity and temperature of surfaces. Multiplewavelength measurements can be done (1) using an array of detectors, each sensitive to a different range of photon energies; (2) using a tunable filter in front of a broad-band infrared detector; or (3) by using a focal plane array of tunable detectors. In choosing a multiplewavelength infrared camera for biomedical research or for clinical practice, the parameters of importance include cost, spectral resolution, spatial resolution, and response time. For many biological systems the assessment of infrared emissivity and/or fluorescence must be done simultaneously with the temperature measurement, because these parameters may rapidly change independently from each other. In addition to providing accurate absolute temperature readings in any thermological study, the measurement of emissivity and fluorescence and the display of their spatial distribution can be especially helpful in dermatology, dermatological oncology, dermatological pharmacology (assessment of pharmacokinetics and of diaphoretic excretion of drug metabolites), skin toxicology, burns management, assessment of radiation overexposure and microtelecalorimetry of cells, micro-organisms and tissue cultures. The measurement of light induced cutaneous vasoconstriction pose novel biomedical research problems that require the use of multiplewavelength cameras. In addition to the use of more sophisticated cameras, precision clinical telethermometry requires a better controlled environment. One must take into account infrared fluorescence, photoreflectance and light induced vasoconstriction all of which are induced by environmental illumination.