human limbs 10 in accordance with the present invention comprising a tubular sleeve member 12 an expandible envelope member 14 and a device 15 for generating gas to inflate the expandible envelope 14 the sleeve member 12 is made of a relatively soft bendable plastic such as transparent polyvinyl chloride or the like the sleeve member 12 has open ends 16 and 18 and is of a size so as to permit a human arm 20 or leg to be conveniently inserted therein the expandible envelope 14 is preferably made of the same soft and bendable plastic material as the sleeve 12 such as transparent polyvinyl chloride the expandible envelope 14 is generally elongated in shape and is encircled by the sleeve 12 in the embodiment of the invention shown in fig1 to 4 the ends 22 and 24 of the envelope 14 project beyond the ends 16 and 18 respectively of the sleeve 12 in its initially flattened form the envelope 14 occupies a minor portion of the sleeve 12 and does not interfere with the sleeve 12 being slipped onto an injured limb the gas generation device 15 may consist of a container of compressed gas which may be opened or ruptured to release gas within the envelope or more preferably it may comprise a store of two or more chemicals which when mixed generate gas the expandible envelope 14 illustrated by way of example contains at least one thin walled capsule or ampoule 26 which may be ruptured or crushed to release a chemical agent 28 which.