Dr Phil Kieran: When do I need to call a doctor about my child's temperature? 

Fever is part of the body’s normal response to infection and we believe its purpose is to reduce bacterial or viral ability to reproduce while helping the immune system combat an unwelcome visitor. 

First things first, we need to specify exactly what a fever is. The normal body temperature is around 37C.  Fever is a temperature of 38C or higher. 

Children's temperature varies more than adults' and is often highest at night so don’t worry about a temp of 37.9C unless there are other concerning symptoms. 

I am most worried about a fever when I don’t know what is causing it. If a child gets a fever during the early stages of a viral infection (runny nose, cough, sore throat/ears, vomiting bug) that’s expected. 

Most viral infections will get better within five days and antibiotics don’t help. If we understand why your child has a fever and there are no other signs that they are very unwell, you can give paracetamol or ibuprofen (stick to paracetamol if you have any concerns about dehydration, like a vomiting bug) and keep an eye on them. 

How you measure temperature is also important. 

Armpit temperature is about the most accurate followed by in-ear. If you measure a child’s temperature when they are very upset and screaming it will be higher, so bear this in mind too.

When do you need to bring a child to the doctor? If your child is less than three months old and has a fever, they need to be seen (unless it is in response to vaccines). 

If your child is less than six months old and the temp is over 39C they should also be seen. After six months the absolute value of the temperature is not as important and there is no cutoff at which they need to be seen - the advice I usually give to parents is to look at the child and trust your instincts.

If your child is moving about and more or less content, this is very reassuring. If they are eating relatively normally and don’t seem dehydrated (moist lips and tongue) and if their skin is a normal colour you can safely monitor them without medical attention. 

If they are pale or lethargic or won’t wake up from their naps, or if they have a new unexpected rash then they should be reviewed quickly by your GP. If you’re worried about their breathing or they are grunting while they breathe,  bring them in regardless of their temperature. 

Also, if the fever goes on for a  sixth day, they should be reviewed.

• If you have a question for Dr Phil,  please send it to parenting@examiner.ie