Among other things, there is provided a system for providing therapeutic cooling or hypothermia to localized areas of the body such as the brain. A source of compressed gas such as a medical-use oxygen canister is connected via a delivery tube to a mask fitted to a patient. The gas undergoes adiabatic cooling as it enters the delivery tube, and is provide to the patient in such cooled state. The system may be provided as a portable or ambulatory device or kit, with the delivery tube or other part easily disconnected from one compressed gas source and connected to another, for continued therapy even during transportation.
