Temperature anomalies associated with oil-producing structures in the US Midcontinent and similar cratonic areas probably can be used reliably as a passkey for petroleum exploration in mature areas, and thus the concept of hot anticlines could be a key to discovery. Analysis of accumulated data during the past several decades allows a definition of the problem of hot anticlines. A possible solution for migration and entrapment of petroleum can be explained by the Roberts temperature differential model and the Walters fluid-flow paradigm. In fact, if the Roberts model is valid, higher shallow temperatures, temperature gradients, or heat flow could indicate the entrapment of hydrocarbons at depth. The recognition and promotion of shallow "hotspots" as an exploration key is not new and was proposed years ago by Haas and Hoffmann, Kappelmeyer, and as recently as 1986 by Blackwell.