A source for reducing drift of a hot spot by producing infrared (IR) light with an insulating housing; an electrical power supply; first and second resistance elements having first and second resistivities; a third resistance element having a third resistivity; the third resistance element disposed between the first and second resistance elements, with the resistivity of the third resistance element having a value greater than the resistivity of both the first and second resistance elements. Alternatively, the first and second resistance elements can have cross-sectional areas that are greater than that of the third resistance. A method of reducing drift of a hot spot in a radiating element of a source of IR illumination by applying constant polarity substantially constant direct current from the power supply and reversing polarity in less than 24 hours, by a square wave AC source, or a Class E amplifier at constant power.