My Husband Is 56. He Is Having Significant Stomach Pain,

My husband is 56. He is having significant stomach pain, achy joints and 101 fever. His right arm hurts. He has a mild to moderate headache. He does not have an appendix. He is constipated and is belching frequently. He vomited today at one point. He feels weak and miserable and does not want to go to the emergency room, but I am concerned