A review of adaptive thermal comfort research since 1998

•Explanation of the discrepancy between PMV and adaptive models is still wanting.•Various adaptive comfort standards are broadly consistent with the exception of GB/T 50,785 (China).•Building typology exerts a discernible effect on occupant comfort.•Boundaries of the comfort zone have become progressively narrower in recent decades.•No credible evidence supports the practice of overcooling buildings to 22 °C for cognitive performance benefits. The rapid escalation of cooling demand in buildings set against the backdrop of a global climate emergency is intensifying research activity on adaptive thermal comfort. In this review of the topic spanning the last 21 years we examine progress or lack thereof, in various research themes. These include adaptive comfort theory, adaptive comfort practice (standards), contextual effects on adaptive comfort (building typologies), shifting boundaries of the comfort zone and the dynamics of comfort expectations. Lastly we assess the implications of adaptive thermal comfort for cognitive performance of building occupants.