This single-use instant hot and cold packs are convenient and cost-effective and can be used for a variety of therapeutic applications. Hot and cold packs provide therapeutic temperatures of approximately 110 °F and 33 °F, respectively, for approximately 45 minutes. Their controlled-release design provides consistent, even thermal therapy, eliminating temperature extremes associated with alternate methods such as ice bags, hot water bottles, heat lamps and towels. Single-use design reduces the risks associated with cross contamination and helps eliminate sterilization/reprocessing maintenance costs.