Ideally you don't want your GPU over 70-75 degrees Celsius. Under load many GPUs can push over 80 degrees Celsius. This isn't ideal as it can shorten the card's lifespan.
If you're worried about GPU temperature there are a number of fixes.
The simplest is to ensure that the vents on the underside of your laptop are not in contact with a surface. This can be done by placing two books barely in contact with the horizontal edges of the laptop, so that the underside of the laptop is elevated off the surface it is resting on.
You can also purchase a Laptop Cooling Pad / Chill Mat which is a device of similar width/length to the laptop with fans mounted on it, to blast cool air at the laptop's underside, keeping it from heating up...