This standard specifies requirements for the application of climate characteristics to workplaces classified as warm or hot, i.e. those exceeding the range of comfort. The severity of work as well as clothing worn during work have been taken into account. The climate characteristics listed below are described, and measurement and data recording guidelines given - Basic Effective Temperature, BET; - Normal Effective Temperature, NET; - Wet Bulb Globe Temperature, WBGT; - Predicted Heat Strain, PHS. This standard gives ranges of orientation for the assessment of the climate at the workplace and in this environment which can be tolerated by human beings. The standard is applicable for workplaces where work is performed regularly and acclimatized persons not wearing heat protection clothing.