This paper uses "cool" as a metaphor to examine the role that affect and social context play in the design and use of knowledge organization (KO) systems. I provide a theoretical basis for beginning this inquiry, then consider the headway made by KO scholars in expanding the paradigm of KO study in order to engage user experience. I then consider how KO may produce affect, and how this aspect may be engaged for further design and study. In conclusion, I look at the value "cool" may have as a commodity in the larger political economy of information.