What is the function of nerves in the dermis?
The nerves provide the brain stimuli from which it can react from.
The nerves will let you feel texture and temperature of your environment and the brain will react depending on that stimuli (example: If you touched a very hot surface, your brain will send signals to your muscles to make you move your hands and arms away from that harmful stimuli.). If someone suffers from 3rd degree burns and recover by chance, they will probably suffer from reduced sensations. The same with those who suffer from chronic diabetes.