Can an inmate complain about their treatment in prison?

We are not able to give you an accurate answer without having some idea of where he is and how much time did he get? There are some state facilities that do not have air conditioning. The lack of soap or menu limited to potatoes sounds pretty minimal, and not within the norm - that is for sure. We would like to think that there is a bit of exaggeration to his complaints, if they are genuine, this is a huge problem and should be reported.