In accordance with at least one aspect of this disclosure, an actuation system for a guided munition, includes a reservoir disposed in a guided munition body housing a compressible fluid in a compressed state, a fluid path connecting the reservoir in fluid communication with a heat exchange volume, a throttling orifice disposed in the fluid path configured to expand the compressible fluid, and an actuation path connecting the heat exchange volume in fluid communication with a moveable component. The actuation path can be configured to supply pneumatic pressure to the moveable components.