Switch operating device (100) with: a presence sensor operating a switch (103) in response to presence of a heat emitting part. The presence has an approach phase (31) during which the part approaches the presence sensor, a remaining phase during which the part remains proximate to the sensor, and a withdrawal phase (41) during which the part is moved away from the sensor. The sensor detects heat emitted by the part with at least one pixel and outputs a signal (51 to 54) with signal deflections (56, 57) corresponding to a temporal intensity curve of heat detected by the pixel. A signal processing unit (101) determines the approach and withdrawal phases from the temporal succession and the shape of the signal deflections. An actuator (104) is controlled by the signal processing unit and operates the switch when the approach phase, the remaining phase and/or the withdrawal phase is determined.