Yes. Unless the fever makes you delerious, it should be okay. Aches and pains from your fever, such as from flu, are less to do with the fever and more to do with the cell damage and death that is occuring.
If you really want to reduce your fever and the detox associated with it, then eat a healthy diet. Eat fresh, cook at home. Begin removing chemicals from your diet. The FDA has us convinced that small amounts of chemicals isn't hurting us. But EVERYTHING has small amounts of toxic chemicals..... It adds up to a toxic overload.
For the best health, a clean diet means:
*no processed dairy
*no refined flour
*no refined oils (very important)
*no added sugar
*no preservatives, or petroleum additives (MSG, BHT, Sodium Benzoate... etc..)
Eat grass-fed beef, free-range chicken & eggs, and wild caught fish
Only cook with pure extra virgin olive oil, sunflower oil, grapeseed oil, or coconut oil
You will notice after several months on this diet you will feel much better, if you get sick you will recover much faster. I used to get the flu every year. Since I started a healthy diet, I only get a minor cold each year. (oh, and DO NOT get the flu shot!)