With my children, it is the other way around, under 23 degrees is already bodily harm. We have already increased the flow rate so that it is warmest in the children's rooms and not over 23 degrees everywhere in the house.
Can I simply reduce the flow by the little wheel? Or do I need to consider something or does it have an impact on the other circuits?
before you manually readjust: simulate the condition first by setting the room thermostat to 18° or less, does anything happen at all (in the heating circuit distributor and actually in the room)? It is also helpful to temporarily hang up a good old thermometer. Because our subjective perception of warmth is not reliable and interprets, for example, a tactilely different floor covering or warm wall colors immediately as "oh, the room is warm"