What bothers me here at IRT 6520 that you have to adjust the age each time prior to measurement (not saved). I think the normal use case is that a person in the household is sick and you then want to measure body temperature at regular intervals.
I would therefore now more likely to buy me IRT 6020 who does not have this "feature". The temperature limits for normal / under / fever you can write on a piece of paper if you do not know that.