Fever

Key points to remember

• fever means the temperature of the inside of the body is higher than normal
• if your child looks unwell and you are worried, take them to a doctor whether they have a fever or not
• if your child has already seen a doctor but they are getting worse, you should take them back for another check
• fever actually helps your child’s body fight off infection
• a fever in a child is usually caused by a viral infection
• a fever may make your child feel unhappy, but even a high body temperature is very unlikely to cause permanent harm
• the reading on the thermometer is not the most important clue to how serious the illness is

Young babies (less than three months old) need more cautious treatment.

• if your baby is unwell or you are worried see a doctor urgently
• young babies cannot control their body temperatures well
• a sick baby may feel hot or cold to the touch
• a thermometer reading is not the most useful way of deciding if your baby is sick

What is fever?

The normal temperature inside your child’s body is around 37 degrees Celsius (but it can be up to 38 degrees). There is a fever when the body temperature is more than 38 degrees Celsius. Fever by itself does not tell you whether your child is seriously sick.

When you measure a child’s temperature, you are trying to tell how hot they are inside the body. This is called the “core temperature”.

The brain helps to control the core temperature and to keep it around the normal level. A young baby (less than three months old) is not as good at controlling their temperature as an older child is.

Fevers are sometimes described as “mild”, or “high”. A mild fever usually means up to 39 degrees Celsius; a high fever usually means more than 39 degrees Celsius.

You can measure a child’s temperature when they feel hot if you want to. But it is not really necessary to do this, especially if your child seems well.

The number on the thermometer cannot tell you:

• what is causing the fever
• how sick your child is