What causes body aches but no fever?

Arthritis...: Body aches can be do to inflammation, degeneration, over activity, fibromyalgia, and many other causes. Without signs of flu, including fever, it is unlikely to be viral myalgia. I would see if symptoms improve with aleve, (naproxen) and if it continues, i advise seeing your doctor!

Poor oxidation: Of tissues. Sometimes called fibromyalgia, it is because the "engines" (mitochondria) are compromised. Commonest cause is poor diet, especially the sugar in all its forms.

Muscle pain: Malnutrition muscle pains autoimmune disease or non febrile viral illness like subacute mono.