Hello,
Fever has traditionally been defined as a rectal temperature over 100.4°F or 38.0°C.It is not life-threatening unless it is extremely and persistently high, such as greater than 107°F (41.6°C) when measured rectally.
It is important to rule out serious causes of fever like meningitis,pneumonia,typhoid and malaria.To rule them out you need specific investigations.
If it is a bacterial infection then it can be confirmed by complete blood count (CBC) and blood culture tests. Specific antibiotics are then prescribed for the infection. Sometimes urine analysis (if suspecting UTI),peripheral blood film(for malarial parasite),widal test(for typhoid),x-ray chest(for pneumonia) and lumbar puncture are required (if suspecting meningitis).I feel that your son should be seen by a pediatrician soon.
Till the time you take your child to the doctor,pls maintain the hydration/fluid electrolyte level of the child by ORS or by juices or drinks which the child likes(except carbonated drinks).Maintain temperature charting and pls do not give aspirin as it can cause Rye’s syndrome. You can keep on giving acetaminophen(Tylenol)or ibuprofen(motrin).
Hope it helps.Take care and pls do keep me posted on how your son is doing.
I would call the doctor when the office opens up and ask. Perhaps they can do a chest x-ray and blood work just to be sure that he doesn't need antibiotics or something.