A cold pack includes a sealed package containing liquid portion and a support structure, with the liquid portion formed of water and menthol isopropyl alcohol in a 4:1 ratio. The support structure is open-cell foam containing interconnected volumes retaining the liquid portion, with cells connected to one another by ligaments. A pack system supports one or more cold packs in pouches for application to a target. Pouches include an insulating layer and a mesh layer that sandwich two large sides of the cold packs, with the mesh layer adjacent to the target, and the insulating layer exposed to the environment. The mesh layer and the insulating layer have a high ratio of thermal conductivity. The pack system includes a waist strap for applying cooling to a human back or a rectangular form for forming into a cylinder-type shape for applying cooling to a horse's leg.