For the past 5 days, I have had fever but like internally. Feeling very hot and getting cold chills on and off. I have body aches toowhat could it be?

See below. At first symptoms sound to be a viral like illness but fever up to five days typically should be evaluated further by a physician. Your symptoms are very vague and still could be a viral illness that is lasted slightly longer then normal. Other infections are possible with fever. Autoimmune and hormonal issues can also present with similar symptoms. Some basic lab testing and a physical are needed.