Why do farmworkers experience heat death more frequently than other outdoor workers, and why are migrant men at particular risk? While heat death may appear a “natural” phenomenon, this book instead implicates U.S. public policies in its production. Drawing upon nearly a decade of ethnography with the same 15 migrant farmworkers, this book examines the way that U.S. labor and immigration policies place them at particular risk in the fields, even as health and social assistance policies offer them little succor when their bodies begin to decline. Yet this book is not about heat death alone; instead, it uses the phenomenon to shed light on migrant farmworkers’ higher burden of chronic illness and cardiovascular mortality at home as well. The introduction addresses the ethical and logistical challenges posed by conducting longitudinal research with vulnerable populations such as migrant farmworkers and makes the case for an advocacy anthropology.