My husband was on a cruise ship at sea, the 2nd day of our trip, He was at the pool reading a book for abt. and hr. or so, around 12pm.  He suddenly started to get chills, and chattering teeth, by the time we got to our cabin, he was freezing and had a very high fever, and bad headache, after a few hrs of tylenol around 5or 6pm his fever broke,  The next day he was fine and 7 days later, he developed a fatigue and achiness all over, but mostly in his neck thighs chest and arms.  He has been sick for 7 wks, no energy,  He is now on prednisone and feeling totally well again, what do you think he had?  We have not gotten a dianosis from any Dr. yet.
Hi Dear, Welcome to Chat Doctor. Understanding your concern. As per your query you have symptoms of high fever with chills and body ache which could be due to infection either by viral or bacterial microorganism. It could be due to compromised immunity of body as well. Need not worry. I would suggest you to take combination of anti-inflammatory medication Cetirizine along with Ibuprofen.  Chat Doctor.  Take painkiller if backache is severe. Avoid intake of outside food. You should take Azithromycin as well as it could be the case of coinfection. Visit General physician once and get it examined. Get blood tests done if symptoms keeps on persisting. Do tepid sponging as well. Hope your concern has been resolved. Get Well Soon. Best Wishes,