Are you talking about your M.2 SSD(s)? With the NUC's - and this essentially applies to all NUC models - support for dissipating SSD heat through the chassis (this is what the thermal foam is for), there is no need for - and indeed no room for - M.2 SSDs that have heat spreaders attached to them. If you have a SSD with heat spreader, it will over-compress the thermal foam and severely reduce the efficiency of its thermal dissipation. Best thing to do is to remove this heat spreader.
This won't help with processor thermal throttling issues regardless. Best thing you can do for this is:
- In BIOS Setup (Visual BIOS), click on Advanced and then Power. In the Primary Power Settings window on the left, uncheck Max Performance Enabled and then check Balanced Enabled. Don't forget to save settings on exit.
- In Windows, click on Start, then Settings, then Power & Sleep and then on the link for Additional Power Settings. Select the Balanced power plan.
With these settings, I have no thermal issues (and fan noise issues are lessened) and the system performs well enough (better to lose a tiny bit of performance than to incur processor throttling).
Hope this helps,