A gel composition possessing good cohesive properties. In one embodiment, the gel composition includes a phase-change material. The phase-change material is preferably an aqueous salt solution. The gel composition also includes a cross-linkable thickener. The cross-linkable thickener preferably is compatible with an aqueous salt solution and preferably includes one or more cross-linkable hydroxyl groups. The gel composition additionally includes a boron-containing cross-linker that is present in an amount that is sufficient to gel the formulation. The weight ratio in the gel composition of boron to thickener is preferably in the range of about 1:250 to 1:50. When packaged in a container, the gel composition resists flowing when the container is torn or punctured. The present invention is also directed at a method of preparing the gel composition, at a thermal exchange implement including the gel composition, and at methods of preparing and using the thermal exchange implement.