Hi,

on a ProfiLux controller it is possible to use Virtual Sensors.
You can create them by browsing the menu directly on the ProfiLux and goto system->virtual sensors.
There are 2 options available:
- Average of two probes
- Copy of a probe

In your case it would be good to use 'average' of 2 temp probes and set the alarm threshold accordingly.
Then assign the new virtual sensor to the desired switch channel/prog logic.