Why do I have a fever all the time?

Actually, I'm asking for my son. He's 38 and has a constant fever of around 100 to 101. He's had it for at least 2 years. His normal temperature is 97.2. He has other symptoms too but I don't know if they're related.
Can anyone help?

 
A fever usually indicates that the body is fighting off an infection.

I think it warrants a checkup by the Doctor.

if he doesn't have any other symptoms but JUST a fever, that is pretty bad. Having a high temperature for no particular reason could mean a hypothalamic problem. Definitely get this checked asap

what are the other symptoms? it is definately something that needs to be looked at by a dr. A fever can be kind of a dangerous thing, and it can cause seizures. There is definately some kind of infection brewing in his body, They will probably check his blood levels and take a white blood cell count, thats the sure way to see if the body is fighting off infection. He could have some sort of auto immune problem. Either way, its something that he should see his primary care dr. for immediately.