Operation Summer Care studies the expanding interest that the hospitality industry takes in the biogeophysical environment. Natural surroundings have long been an essential operational precondition of tourism in the global sunbelt, but contemporary environmental anxieties increasingly motivate different strata of hosts to take a more active role in environmental management. Usually the domain of the state, biogeophysical entities and their spaces—plants and animals, sand formations, wetlands, entire ecosystems and protected areas—are measured, ordered, and managed by actors adjacent to the tourism industry. At the same time, the socio-technical mechanisms of environmental intervention and calculation are conveniently framed as practices of care and stewardship for the shared infrastructures of the summer. Attending to both these tendencies, the project examines how, and through which narratives, the hospitality industry overlaps with environmental science and management to create the conditions for a calculative governance of the biogeophysical. The apparatus of this relatively novel and evolving entanglement between the tourism industry and environmental management—one that involves not just hotels, operators, and tourists, but also municipalities, NGOs, civilian associations, research institutes, activists, awards, standards, and new technologies—is what I call the stewardship-hospitality complex. To understand the phenomenon, I review three empirical cases in Greece, in which the techno-scientific apparatus of environmental calculation mixes with fables of both paradisic quiescence and planetary stewardship: a popular eco-certification scheme for beaches, the environmental management practices of a large hospitality corporation, and an island municipality’s responses to geologic events. In all three cases I show how stewardship and hospitality weave into each other, strengthening both the moral and infrastructural apparatus of tourism in the global sunbelt. Amidst the interrelated imaginaries of ecological collapse and Anthropocenic care, environmental stewardship is presented as yet another benefit that tourism can offer. As a result, not only is the identity of “the host” infused with imaginaries of “the environmental steward,” but also coastal natures are fixed with tourism, as their organization and priorities are defined through the programs of human leisure.