Abstract: A small, inexpensive, but reliable pressure warning system includes a plurality of pressure sensors which are disposed between an orthopedic restraining member and an injured portion of a patient's body, and a processor and alarm unit coupled to the pressure sensor and providing a warning when the pressure reaches a danger level (i.e. 30 mm) in which medical assistance is required. If the pressure goes above a critical value (i.e. 35 mm), another warning is provided that immediate medical attention is needed. The processor and alarm unit can be mounted directly on the patient's cast and are disposable, one-use items.