Start by changing your hand position. If you tend to put a lot of pressure on particular areas of your hands, it may impinge on the nerves. Try changing how you load your hands and see if you can find a position that's more comfortable and causes less strain.
You can also change the angle of the pbars by angling them more inward or outward, and see if that helps.
Other tips: Try adding using some sort of padding, even a towel can work, to take pressure off your hands. Try doing fewer repetitions but more sets to decrease continuous time on the bars but maintain training volume.
This video has some more info on preventing hand pain and numbness while training.