Body Temperature and Fever in Toddlers

Fever is a sign that your toddler is fighting an infection. As parents, it’s important to know what to do when your child has a fever. Here is some handy advice on how to tell if a fever is serious and, if so, how to treat it.

It is generally accepted by medical professionals that the normal body temperature for a healthy child is between 97 and 100.4 degrees Fahrenheit (36 to 38 degrees Celsius). When a child’s temperature goes above this range, they have a fever. In children under five, the parameters are slightly different and a fever in a youngster of this age is considered to be a temperature over 37.5C (99.5F).

If your toddler develops a fever (also known as a pyrexia), it’s usually a sign that their body is fighting an infection. Fever in toddlers helps the body to combat the bacteria and viruses (the pathogens) that cause infections by stimulating its defences, such as by creating an optimum environment for white blood cells to do their work in. By increasing the body’s temperature, a fever makes it harder for pathogens to survive. In particular, fever in children is believed to ‘train’ their immune system and may help prevent asthma.


Most fevers are caused by an infection or other illness. Medical conditions that can cause fever include:

  • Colds and flu
  • Ear infections
  • Roseola (a virus that causes a temperature and rash)
  • Tonsillitis
  • UTI (urinary tract infection)
  • Measles
  • Mumps
  • Chickenpox

Other causes of a raised temperature in a toddler:

  • Overheating (because of inadequate air conditioning, or too much bedding or clothing)
  • Teething
  • Immunisation

How can I tell if my toddler’s fever is a sign of something serious?

A temperature reading on its own should not be the only indication of whether your child has a fever. The human body goes through a natural diurnal temperature range that sees higher body temperatures in the later part of the day and evening and lower temperatures from midnight to early morning, so you should expect to see variations.  Your toddler will have a higher temperature during energetic play than they will have after they have just woken up from a nap, as their metabolism will slow down during sleeping. If you are taking your toddler’s temperature orally, you should ensure that they haven’t consumed any hot liquids for at least five minutes before inserting the thermometer, otherwise you may get a false high result.


When should I call the doctor?

The bottom line is that you are the best judge of your child as you know them better than anyone else. If you are in any way concerned, you should call the doctor, no matter what their temperature is. Your toddler’s behaviour is the most important indicator of how well they are. If they appear well, there’s no need to call the doctor unless the fever is very high, has persisted for more than 24 hours, or there are additional symptoms, such as drowsiness, earache, stomach pains, coughing, vomiting, or diarrhoea.

Additional guidelines

You should also call the doctor if you observe the following:

  • You notice a rash, or purple blotches on your child’s body, which may indicate a more serious problem.
  • Your child has not drunk fluids for over eight hours
  • Your child is noticeably pale or flushed
  • Your child is passing less urine.
  • Your child has difficulty breathing

Treating a fever

Physical ways to keep your toddler cool include the following:

  • Removal of tight fitting clothing, allowing only loose garments or no clothes at all
  • Increasing the air conditioning
  • Use of a fan to circulate air
  • Tepid bathing (do not use cold water, as this constricts the skin and traps heat in)

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