Child Has Weakness, Black Circles, Fever, Sweating. Taken Children's Advil. Any Suggestions?

Tonight my four year old was very weak and pale before he went to bed. He seemed to have black circles around his eyes. He also seemed to have a fever. I gave him children's advil right before bed. I went in to check on him about an hour later and he was drenched in sweat. We got him up changed his bed, gave him a bath, and got him back in bed. A few hours later we checked on him and he had sweated profusely again. He has not really complained too much about anything, but has been awfully weak and snotty recently. It is important to mention that he has been diagnosed with Reactive Airway disease and when he got very croupy we gave him a treatment at the advice of our doctor. Any suggestions?