Abstract: A resuscitator has two separate, spaced controls (23) and (30) both of which can be actuated manually to open a valve (100) and deliver a breathing cycle of a maximum timed duration to a patient. One control (23) has a button (24) on the top (13) of the unit (1), which is pushed in to actuate. A ring (25) surrounds the button (24) and has cam profiles (122) that engage with cam pins (120) on the button to push and hold it down when rotated. The other control (30) is on the underside surface (14), facing the patient and adjacent the gas outlet (5). This control includes a toggle lever (31), which can be displaced laterally in two different planes to open the valve (100).