Although an adults skin is tougher than a baby or toddlers skin it is possible to get diaper rash if an adult is wearing diapers.
You should apply diaper rash cream to your butt and groin area before putting the diaper on and you should change out of the diaper as soon as you wake up and take a shower to get the urine off of you.
Try not to wait too long before changing out of the wet diaper. Just like you should change a babies diaper often you should do the same as an adult wearing diapers.