In this work, the literature about the relationship between thermal comfort and productivity in workplaces is reviewed and explored by means of a co-citation analysis—i.e., a factor analysis applied to the mutual citations of the most relevant contributions. A structure of three main clusters of papers describing the relationships between workers’ thermal comfort and productivity were identified according to the factor analysis and then confirmed with a multidimensional scaling. Results indicate that comfortable indoor thermal conditions can have beneficial impacts on workers’ well-being and productivity, such as higher operational rates, lower production losses, fewer sick leaves, and reduced health related costs. Some authors proposed analytical and empirical expressions for the quantification of the impact of thermal comfort on productivity; nevertheless, due to the broad spectrum of activities and their applicability, the literature is still far from reaching a general consensus on the potential impact of comfort/discomfort on productivity and proposed models can vary significantly in the different studies.