A chemically-activated conformable thermal device that generates heat upon activation is provided. The thermal device typically contains an oxidizable metal that is capable of undergoing an exothermic reaction in the presence of moisture and air to generate heat. Although such metals, as well as other components of the composition (e.g., carbon), are relatively inflexible and stiff, the present inventors have nevertheless discovered that one or more conformable segments may be employed to impart flexibility and conformability to the thermal device. The conformable segments are malleable so that they yield under shear stress and acquire the shape of a surface (e.g., body part) without rupturing. The conformable segments are likewise stiff or hard enough to substantially retain the desired shape during use.
