A good temperature for your desktop computer's CPU is around 120℉ when idle, and under 175℉ when under stress. If you're using a laptop, you should look for CPU temperatures between 140℉ and 190℉. If your CPU heats up beyond about 200℉, your computer can experience glitches, or simply shut down.

Is 70c too hot for CPU?

70-80c is normal range for a CPU under full load. Only worry about temps over 80c.

What is a good CPU temp for gaming?

70 degrees is a very reasonable temperature. I hope you mean fahrenheit. CPUs can run at that temp and be fine. Most CPUs have a thermal threshold of around 100 Celsius, if the CPU hits that the computer will shut down.