What Causes A Chronic Feeling Of Burning Up On The Inside?

Male, 25, high metabolism, 6 foot. 135 pounds, sinus problems. Has no fever to touch but feels as though he is burning up internally. This is daily. His thyroid was checked and it s normal. What could be wrong. He has had this issue for 2 years and is miserable. When it happens nothing will relieve the feeling of fever. Hydration is not the problem. He can chug water and sit in front of a fan with no relief. What is suggested to help him??