Abstract: In a panic bolt assembly for use on an emergency exit door, a horizontal elongate operating device comprises two elongate bodies hinged together along adjoining horizontal edges. Each body is pivotally mounted on the door about a horizontal axis adjacent the edge of the body remote from the hinged edges. At least one of these pivoted edges is constrained to move vertically with respect to the door to effect engagement or disengagement of a bolt of the door. Pressure imparted to the hinged edges of the device in a direction towards the door effects vertical movement of the pivoted edge or edges to disengage the bolt or bolts.