Book excerpt: In Media Hot and Cold Nicole Starosielski examines the cultural dimensions of temperature to theorize the ways heat and cold can be used as a means of communication, subjugation, and control. Diving into the history of thermal media, from infrared cameras to thermostats to torture sweatboxes, Starosielski explores the many meanings and messages of temperature. During the twentieth century, heat and cold were broadcast through mass thermal media. Today, digital thermal media such as bodily air conditioners offer personalized forms of thermal communication and comfort. Although these new media promise to help mitigate the uneven effects of climate change, Starosielski shows how they can operate as a form of biopower by determining who has the ability to control their own thermal environment. In this way, thermal media can enact thermal violence in ways that reinforce racialized, colonial, gendered, and sexualized hierarchies. By outlining how the control of temperature reveals power relations, Starosielski offers a framework to better understand the dramatic transformations of hot and cold media in the twenty-first century.