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.