The Universal Thermal Climate Index UTCI Goal and state of COST Action 730

The heat exchange between the human body and its environment takes place by sensible and latent heat fluxes, radiation and (generally negligible) conduction. Consequently dealing with the thermophysiologically significant assessment of the thermal environment requires the application of a complete heat budget model that takes all mechanisms of heat exchange into account. Input variables include air temperature, water vapour pressure, wind velocity, mean radiant temperature including the shortand long-wave radiation fluxes of the atmosphere, in addition to metabolic rate and clothing insulation. Based on current advances in science of heat budget modelling there is a need for harmonisation of the development and dissemination of a universally valid health related climate index.