Presents the findings of an ASHRAE field study of occupant comfort and thermal environments in 12 mechanically ventilated office buildings in southern Quebec. 877 occupants were surveyed during the hot and cold months. Each interview provided a set of responses to a questionnaire and a set of physical indoor climatic measurements. Notes that the incremental effect of chairs was included in the estimates of clo values. Presents the findings and makes recommendations. Concludes that occupants' responses to indoor climates in an extremely cold climate differ from those in mid-latitude and tropical climatic zones.Units: DualKEYWORDS: year 1997, Offices, comfort, research, Canada, cold regions, indoor, climate, thermal comfort, mechanical ventilation