Provided is a body temperature regulation pack which uses a solid-liquid phase change material to prevent body temperature increase or body temperature decrease of a wearer. When the pack is arranged on the inner side of a pack holder to be worn under clothing, the pack may be bent along a body shape even in a solid state. Even when the phase change material is in a liquid phase, the outer shape of the pack does not deform regardless of the orientation of the pack. The pack has a substantially tabular shape as a whole, and has high heat absorbing ability or heat releasing ability. In a body temperature regulation pack having a solid-liquid phase change material filled therein, the pack includes a plurality of bag members arranged in parallel to each other. The bag members are each filled with the phase change material without gaps.
