Will mining damage my CPU or GPU over time?

Mining is not inherently more damaging than other sustained workloads like gaming, video rendering, or scientific computing. What matters is heat and dust. A GPU running at 65 degrees Celsius for years will be fine; one running at 90 degrees Celsius constantly will not be. Keep temperatures in the safe range by capping power, cleaning fans, and ensuring good case airflow. Replace thermal paste on older cards after a couple of years if temperatures creep up. Avoid aggressive overclocks - the small hashrate gain is not worth shortened hardware life. With reasonable settings, the hardware will likely become obsolete long before it physically wears out from mining.