There is a photo of inside of lower case?
i buy second-hand mbp mid 2012 13" with 16 Gb RAM, and HWMonitor shows memory module 1 temp around 75 - 77 celsium, who is a bit too high, i think.
open lower case, clean off dust, and see on a lower case inside, in place, where is memory modules, is additional insulation foam layer. dont know - that is from apple, or previous owner put that on its own?
in any case 77 celsium on memory is too high temp, i think. have also 2011 late mbp 13" also with 16 Gb ram, and there typical temp on mem module 1 shows about 52 -55 celsium - almost as half lower than on mid 2012....