The most probable disease in this case is an upper respiratory tract infection which is mostly viral caused. His temperature should be kept normal by giving paracetamol(which you are already giving) and by cold sponging, if needed. other symptomatic treatments such as antihistamine syrups relieve the other symptoms such as throat tickle,congestion and itching eyes. good hydration and maximum rest is recommended, but if any new symptoms like vomiting, breathing difficulty ,loose motions etc start, immediate medical attention must be seeked