Abstract: A therapeutic sleeve and techniques for using it are provided. A therapeutic sleeve may house a conduit carrying a constant stream of a chilled or heated working fluid throughout the sleeve. A heating element may evenly distribute heat throughout the sleeve. The sleeve may provide a precise temperature-controlled pocket that significantly improves treatment of pain or discomfort in the user's feet, head, or other body parts. A software application may enable a user to set or adjust a temperature, set timers, record sleep patterns, and view analytics or other data.