Yes, I tested it by leaving the box open in the open air (I did that multiple times already), also in a shaded place. So at that point, the temperature should be the same as the outside temperature, which was not the case, since there was still an offset of the same amount. I therefore think that the offset is constant and the box does not ‘warm up’ by the smart implant.
Could this mean my Smart Implant is broken, because nobody seems to have this problem?
-Edit: there are no other components in the box that could cause any heating of the box-