A relation between gravimetric and thermal anomalies, Q = F (A/2πGρ), where Q is the rate of heat flow, A is the rate of heat production per unit volume, G is the gravitational constant, ρ is density, and F is the gravitational attraction, is used to obtain theoretical surface heat flow anomalies for bodies from the analogous theoretical gravity anomalies. Results are collected for several geometrical shapes, and the application to digital computation of sources of arbitrary shape is indicated. The same relation may be used to verify that a gravity anomaly and a heat flow anomaly are caused by the same body.