Multistage control of temperatures in liquid or gasiform media, e.g. for the triggering of two-stage burners or coil heating systems. The protective spiral SW-200-12 is determined for use with all temperature control tasks within non-aggressive types of gas that flow in conduits, while the dip sleeve TH is determined for all control tasks within non-aggressive fluids. The application of the dip sleeve type NTH is required when using the device for the control of temperatures in aggressive fluids.