The Heat of Desire generates a scene by rotating image fragments at high speed. The rotation is triggered by the behavior of a temperature sensor that enables the motor circuit at a well-defined temperature, 27 C, the heat of desire. The opposition of the Umbrella Salt Girl and the hobby scientist is visible only beyond this threshold temperature. The materials used are wood, plexiglas, paper, a heat sensor, a direct current motor and a 1.5-volt battery.