The main purpose of this monograph is to provide a comprehensive study of the effects of thermal radiation on both man and materials, for use in the assessment of risks and hazards from fires and fireballs. The study was sponsored by the UK Health and Safety Executive (HSE) with the aim of producing a useful reference document for work connected with major hazards assessment for land-use planning and in developing operational standards. The monograph is based on an earlier report (1984) and revised to include more recent information on the effects of atmospheric transmissivity on thermal radiation, the effects of thermal fluxes incident on clothing materials and the prognosis of burn-injury victims. The Glasstone method previously used to account for atmospheric transmissivity has been replaced by a model which considers the attenuation of radiation by both scattering and atmospheric absorption. A methodology has been included which enables ignition and melting times of fabrics to be predicted. Knowledge of how a fabric is likely to respond to a particular incident flux provides for a more comprehensive means of predicting the consequences of a person's exposure to thermal radiation. The assessment of thermal radiation consequences has been extended to include a section describing the prognosis of burn-injury victims. Given a particular level of injury, it is possible to estimate the mortality probability of a victim knowing the victim's age and percentage body area suffering from burn injury. The first IChemE monograph on thermal radiation, "Calculation of the Intensity of Thermal Radiation from Large Fires", dealt with classification of fires and methods of calculation of thermal radiation for different types of fires. It complements this monograph.