Abstract: A compression device for human limbs including a flexible sleeve and an expandible envelope which contains a pair of chemical agents which form a gas when mixed. In use, the chemical agents are mixed by manual manipulation of the expandible envelope, creating a gas which expands the envelope causing the envelope and the sleeve to bear against and to support an injured limb which has been inserted into the sleeve, thereby serving as a splint for broken bones or as a pressure dressing for the control of bleeding. The device may comprise a sleeve surrounding the injured limb and the envelope or, alternatively, a flexible panel forming a sleeve-like opening in which the limb is inserted.