What can cause brain numbness fever and congestion?

Absolutely, to CS: The nose is part of the so-called danger triangle because much of the venous drainage goes up in the cavernous sinuses, a complex a veins under the center edges of the frontal lobes of the brain in which blood flow is both complex & slow. Thus infections or anything else introduced into the skin, mucous membranes, etc. Of this area can end up setting out within cerebral veins, drive lots of damage.

Not sensible: Fever is usually caused by an infection. 'congestion' usually means, to a lay person, nasal sinus obstruction with mucus and fluid. The brain can't be 'numb', this part of your question is not sensible. See a doctor and explain your symptoms more clearly to him or her to get clear answers.