Definition:

If the temperature of your child exceeds the following, they have a fever:

•                Rectal temperature exceeds 38°C (100.4°F)
•                Oral temperature exceeds 37.5°C (99.5°F)
•                Armpit temperature exceeds 37°C (98.6°F)

Children’s armpit temperature is usually around 36.5°C, and fluctuates within the day. Exercise, warm clothes, hot shower or a hot day could all raise their armpit temperature to above 37.5~38°C; hot food or drinks could also raise their oral temperature. If you doubt the higher than usual temperature of your child relates to the factors above, make a measurement again after half an hour.

Reason:

Fever is a symptom and not an illness or disease; it is our body’s reaction to bacteria, virus and or other infections, a sign that our body’s defence mechanism is fighting these outer enemies. Fever usually results an armpit temperature of 37.3~39.5°C, with an extra 0.5°C for oral temperature and 1°C for rectal temperature. Temperature at this range is not harmful to your child so there’s not too much to worry about. There are many reasons that could cause a fever, mostly seen are bacterial infection, some are virus related. Growing new teeth does not cause fever. Even though most bacterial infection will cure naturally, but it’s still best to consult your family doctor when your child has a fever, in case we missed some infection that require special treatment.

How long does fever last?

Most bacterial infection caused fever would have an armpit temperature of 37.8 to 39.5°C, and lasting two to three days. Normally speaking, your child’s body temperature does not necessarily correlate to the degree of illness. Instead, what reflects the degree of illness is often how uncomfortable your child looks like (referring to just after when the fever is gone, since during fever everyone feels bad). A fever with armpit temperature of less than 41.2°C does not cause any damage to the brain, so it is false to think that the fever is going to burn/damage the brain; our brain has its own built in temperature regulator mechanism that keeps our brain temperature within a certain range.

Even though most children experience fever from time to time, only about 4% of the children will have fever seizure; and normally speaking fever seizure is not harmful to your child, so there’s not too much to worry about.

Dr. Z