I have 6 Macs, including the DTK , and get nearly as hot at idling as my Mac Mini 2018 i7 3.2 GHz (64 GB RAM, 1 TB SSD).
iStat shows every temp, from CPU over GPU, SSD and Memory, in the 42-48 deg C area, with the Mac (10.15.6) being idle at 98-99% for a while. The case feels similarly warm, like a little oven (which I really don't need during these hot summer days, thank you). The fans don't run noisily.
I wonder if that's unusually high, ie. that my Mac has a defect (such as a bad heat sink connection) and should be serviced.
What do others see when their i7 is idling? Same range, or are the temps below the 40s C?
Same range. These machines are designed to run hot. Disabling turbo boost makes it run cooler when under moderate to heavy use.