Did u check the temperature with a thermometer? Use a thermometer to check the temperature. If it is 37.5C and above,the child has fever. You should bring down temperature by exposing child, tepid sponging with warm water and giving paracetamol. They are many causes of fever. Please take child to see a paediatrician who will carry out tests to know cause of fever and provide appropriate treatment.
Please do not self medicate.