Windows 10 & prime95:
Cpuid HWMonitor provides no core temp output
Cpuid HWInfo crashes after displaying some cpu loadings
CoreTemp
https://www.alcpu.com/CoreTemp/ runs out of screen height, displaying 28 of 68 cores, with some interesting loading figures. The temps are comparable to Ernst's. Note the cooling is effective enough that with 32% cpu loading (25% would be one saturating task per physical core, due to the way Windows handles hyperthreading), a degree of turbo clocking still occurs. Nominal is 1.4, full turbo is 1.5 Ghz, I've seen 1.42 and 1.44 with full prime95 load.
But when minimized, CoreTemp goes to the System Tray. Bringing up the System Tray shows a real time temp for each of the 68 cores there. Highest I've seen is 56C, and the house ambient here may be higher than Ernst's apartment.
Open Hardware Monitor
https://openhardwaremonitor.org/downloads/ displays loads for the first 60 cores but no temps.