An occupant support 20 augmented with a detection system for assessing the condition of an occupant includes first and second detectors 58, 62 for detecting presence of the occupant, an occupancy detector for determining if the occupant is occupying the occupant support and an analyzer for assessing whether a presence indication from each of the first and second detectors and an occupancy indication from the occupancy detector correspond to a satisfactory condition of the occupant or an unsatisfactory condition of the occupant. A presence detection system for determining the condition of a target comprises a first and second detectors for detecting presence of the target in first and second regions, and an analyzer for assessing whether presence indications established by the presence detectors correspond to a satisfactory condition of the target or an unsatisfactory condition of the target.