A fever may, but does not always, accompany a bladder infection. Children may sometimes run a fever with a bladder infection. Other signs to watch for include nausea, smelly urine, or loss of appetite. If your child has a high fever without signs of a cold for more than a day, consult a doctor to check for a bladder infection. Fever is not a common sign of bladder infection for adults but may occur, especially if the infection has spread.