I guess I understand. Indeed the flow from my first reply will not help you. I need to think over but it is too late already in my time zone.
Just a question. How would it possible to track a temperature trend if anyone can open the fridge door at random ? Is it a good approach to track a trend given that the temperature can be disrupted at any time, several times during the time frame ?
I wonder if this use case is similar to a previous one in this forum about tracking humidity trend. The solution was not trivial at all.