What is your ambient temps? Are you living in a cold climate since 20C+ for a non OC is pretty low. 😱
Based on the ambient temps here, a Core i7 2600 has a 40C idle temp with a Hyper212+. It loads to 60C max but your CPU below 80C should be just fine although ideally lower temps are better.
I doubt it would die in 3 years time from such temps but you could try dropping the temps a little by decreasing the Vcore till you reach a stable range for that speed. You could try decreasing the temps by improving case airflow by adding more fans or reduce cable clutter. Adding another 120mm fan to the Hyper212+ for a push pull configuration helps reduce the temps as well.Ambient temp is about 30deg +-5. Yeah thinking about clocking it a bit less so it doesnt die in 3 years 😛.