Tobacco smoking article with electrochemical heat source

A smoking article with an electrochemical heat source is disclosed. The non-combustion heat source includes at least two metallic agents capable of interacting electrochemically with one another, such as magnesium and iron or nickel. The metallic agents may be provided in a variety of forms, including a frozen melt, a bimetallic foil, wire of a first metal wrapped around strands of a different metal, and a mechanical alloy. The metallic agents may be in the form of a powder filling a straw, or small particles extruded with a binder or pressed to form a rod. Preferably, the heat source is self-extinguishing if ignited. The powder filled straw or rod may be placed in a heat chamber surrounded by tobacco. An electrolyte solution contacts the metallic agents in the heat chamber to initiate the electrochemical interaction, generating heat which in turn volatilizes the nicotine and flavor materials in the tobacco. Preferably, any gases from the heat chamber are directed away from air intake holes through which air enters the smoking article.