Core Temperature Norms and Limits

The Antipodes solution dashboard for my K21 show CPU Usage, Memory Usage and Core Temp. I can understand the reason displaying this information, but there does not appear to be any information on what levels are cause for concern and perhaps what actions should be taken if too high. Memory and CPU Usage are probably more of FYI, but what would be considered yellow and red limits for Core Temperature. Looking elsewhere on the forum 40C appears to be the norm for many models (which is what mine runs statically and dynamically), but what temperature would be cause for the durability of the electronics.

As long as you give it airflow you will not experience problems, it is designed to work with temperature fluctuations.
The device will shut down at 90 degrees, which is cause for concern.