Technically i believe the GPU can be a bit higher than what the CPU runs at.
CPU's have a threshold of about 100C forcing an automatic shut down, Graphics cards have them about 20C higher than that
At 70 under load that is bordering quite Hot but ok, as long as it doesn't hit 80C and over at that temp it could start causing damage.
The same with a CPU over 60C and that could start causing damage.
Which Graphics Card do you have?
Normally a Idle temp around 50-60C is what is normally seen and around 70-80C when under load for GPU's, Because this is only a rough estimate on GPU's yours may be different