This article describes thermal vision, the ways of seeing invisible thermal emissions and exchanges. While most studies of thermal vision have focused on the deployment of infrared imaging in military and police operations, the author articulates thermal vision as a perceptual mode that both extends beyond the infrared camera to a broader set of practices of seeing heat as well as beyond the militarized view to scientific, commercial, and cultural landscapes. Weaving through these practices and landscapes, she outlines four overlapping ways that thermal vision is oriented and in turn organizes the world: through thermal effects, hue, objects, and zones. Focusing on the latter form, and taking cases from early infrared photography in the 1930s and the expansion of building thermography in the 1970s, she argues that the thermal imagery used for visual surveillance, often as a means of objectification and targeting, is intimately connected to regimes of environmental monitoring and the creation and management of normative zones. A close attention to these cases draws out one of thermal vision's critical affordances and cultural uses, regardless of technological platform or orientation: entangled with practices of temperature control and synesthetic processing, it has been enlisted to alter architectures, environments, and bodily movements through them. Observing these uses expands visual culture studies' understanding of the sensory possibilities of the visible and helps scholars to track the affective and intimate dimensions of climate change.