The processor temperature can be between 40 C to 75 C depending on the usage of the processor and the task it is trying to complete.
It is considered as overheating when the processor reaches more than 92-95 C and after the 102 C the processor will shut down automatically for security reasons.
In regards your question; the i7 can handle the same temperature than i3 and i5 processors.
My best recommendation based on your description is top verify the heat sink has been set properly and check that there is enough thermal material on the processor to cool it down. Also, taking the motherboard outside of the chassis can help to diagnose any airflow problem with your system.