Extra cooler for Pentium Dual-core

Hi, my dual core cpu's temp is 43c in ideal but nearly 68c or 69c when playing games at high setting. Is it safe & Do i need to use exrta cpu cooler? Will it reduce my cpu performance during gameply?

My cpu model is Pentium Dual-core E5400 2.70 Ghz. If this temp is okey & no need to buy a cpu cooler, then i will spend more money to upgrade my gpu. I want to upgrade hd4650 to hd5770 gpu.

Thank you.