South African novelist Olive Schreiner suffered from lifelong health difficulties, including malaria. This chapter thinks critically about how to read her personal illness alongside her artistic production. It argues that Schreiner draws upon female colonial settlers’ lived experience of chronic malaria in order to form her critique of colonial medical logic, which is based on a ‘metonymy of exchange’ whereby colonial bodies and environments are epitomized by their productive value. This chapter traces how representations of malaria evolve in Schreiner's fiction. Her earliest work, Undine, depicts the corruption and risks of colonial capitalism in terms of ‘camp fever’. In Story on an African Farm, Schreiner breaks open the form of disease allegory to question colonial-meaning making. In her last novel, From Man to Man, Schreiner shows female characters allied with the traditionally ‘threatening’ aspects of the colonial environment, such as extreme heat and insects. The chapter argues that Schreiner’s project was timely and important, as the eradication of mosquitoes, specifically feminized mosquitoes, became central to colonial medical discourse in early-twentieth-century South Africa.