Our 70 Year Old Male Friend, Has Had Many Health

Our 70 year old male friend, has had many health struggles over the years, including a traumatic brain injury (MVA), cerebral aneurysm, stroke, surgery for a herniated disc, and several reoccurances of lymphoma, which were treated with chemo, radiation &/or surgery to remove the 'lumps'. After his stroke he was unable to walk or talk, and was totally dependent. In the past several years he has recovered to the point that he is now totally independent, and was even able to get his driver's license back again! His only remaining deficit is with his speech, he still struggles to get the words out. However, he hasn't been feeling for several weeks, extreme fatigue and in the last 5 evening he gets the chills and then develops a fever. Last night his temp was 104.6. He went to see his GP today and was told that his blood & urine tests were normal, his chest didn't sound bad enough to be causing the fever, and that it probably isn't caused by his cancer, because it would cause a low grade fever. He was sent away with no clear diagnosis and was asked to go to the ER if his temp spikes again tonight. He does not have a fever during the day. Any suggestions would be greatly appreciated. Thank you, Sherry