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??