We set out by noting the preference for circular flows in ecological thought, and the related abhorrence of inefficiency and waste that Western ecology shares with mainstream economic thinking. This has often been manifest in a shared disdain both for uncontained, free-burning fire and for ‘unmanaged’ sexual desire. The paper constructs a ‘pyrosexual’ counter-narrative that explores the mutually constitutive and generative implication of sex and fire. Bringing together the solar ecology of Georges Bataille, feminist and queer thinking about sexuality and (...) reproduction, and a range of ways of theorising biological life and fire, we explore how fire mediates between organismic desire and the energetic dynamics of the earth and solar system. The first section takes a genealogical approach to fire and sex that traces their entanglement from the initial ‘assembling’ of fire through to the emergence of a fire-handling creature. The second section looks at how fire has been contained and intensified by human actors, and the role that heat-driven transformations of inorganic matter have played in the incitement and channeling of desire in urban spaces. The third section addresses the development of industrial ‘heat engines’ and the implications for desire and reproduction of tapping vast reservoirs of subterranean solar energy. We round off by beginning to consider what alternative possibilities might lie in the renegotiation of sex and fire on a planet undergoing rapid change. (shrink)