A guard structure of a patient support, such as a hospital bed, is electrically unlockable. An electromechanical actuator, such as a solenoid, may be used to electrically unlock the guard structure. The guard structure may also be mechanically unlockable. The guard structure may automatically unlock during a CPR emergency. A maximum allowable height of the patient support may be adjusted based on a sensed locked state or position of the guard structure. A release for the guard structure may be positioned to be accessible to an occupant of the patient support. The release may include an access port that may be opened. The release may include a button that electrically unlocks the guard structure.