Setting out from accounts of metal working by authors Colson Whitehead and Toni Morrison, the paper looks at how heat-induced transformation of inorganic matter is at once a condition of possibility of modern politics and tends to overflow politicization. While Anthropocene science directs attention to the interaction between the flows of the outer Earth system and the rocky layers of the planet’s crust, geoscientists have also been exploring the juncture between the exterior and the sub-crustal interior of the Earth. Looking at the manipulation of fire by our most distant ancestors and by artisans in the ancient world, I suggest that humans have effectively used high heat as a means of mediating or articulating between the inner and the outer Earth. But if we conceive of the hearth – the symbolic centre of the polis for Heidegger and others – as a formative site of high heat use, then there is something at once mundane or this-worldly and profoundly excessive or other-worldly about the relationship between high heat technics and the political. This leads to some infrapolitical considerations both about attempts to assimilate geo-cosmic exteriority and about finding ways to live with the unassimilability or withdrawal of the Earth and its forces.