The biological effects of infrared exposures were discussed, with specific attention given to the effects on the eyes and the skin. Infrared radiation production, characteristics, sources, occupational exposure, and measurement instrumentation were described. Ocular hazards were considered, including effects on the eyelid, the cornea, the aqueous humor, the iris, the lens and the retina. While damage thresholds determined experimentally were based on exposure to the lowest single dose causing the damage, determinations of industrial damage thresholds should be based on many exposures to the lowest dose over many years that will produce such damage. Hazards to the skin were also discussed, including human skin reflectance as a function of wavelength for different pigmentation, the scattering of transmitted energy under normal incident radiation with skin samples of various thickness, and the spectral transmittance of excised human breast skin. Other hazards discussed included vascular congestion in the spleen and kidneys, an analgesic effect on specific nerve areas, damage to upper respiratory passages of iron foundry workers, thermal insult to the testicles, the incidence of postoperative intestinal adhesions and microscopic intestinal injury resulting from the use of overhead infrared heating lamps, possible genetic effects, and very little direct or indirect evidence of the carcinogenic potential of infrared radiation. The existing exposure standards and control methods were reviewed.