The Temperature Compensated Stored Gas inflator provides output gas which is completely clean and cool, with significantly narrower temperature dependence than a traditional stored gas inflator. During discharge, the exiting gas which has been cooled by decompression can be reheated by flowing through a passive thermal reservoir. A valving device maximizes this heat addition at cold initial conditions and minimizes heat addition at hot initial conditions. The inflator is simple in principle with few parts, completely free of particulate emissions, and environmentally attractive. Pulse-shaping is also provided by mechanical means.