No, 60C is not too hot for the NB, it is rated to an incredible 105C. However, 60C suggest to me poor case airflow.
Q - What Case?
Q - How many Case Fans are installed; e.g. 120mm front/in, 120mm rear/out, etc.?
Suggested Tests:
1. run Prime95 15 minutes with side panel off {post temps}
2. cool off/shut down 10 minutes
3. run Prime95 15 minutes with side panel on {post temps}