The authors present the results of measurements made at four industrial sites to assess the optical hazards and thermal stress to workers exposed to infrared sources. From an analysis of the measured radiance levels, there is no reason to anticipate the existence of potential hazards to the retina from either photochemical or burn injuries. Consideration of the irradiances (770-1400 nm) associated with four sources at a small glass works and a foundry suggest that workers should use suitable eye-wear to protect against possible damage to the lens of the eye. The thermal loads experienced by workers, engaged in their normal work activities, close to the sources are not considered likely to produce symptoms of thermal stress.