Understanding Fever in Children
Educational information about fever, warning signs, hydration and when to seek medical advice.
What Is Considered A Fever?
Most healthcare organisations define fever as a temperature of 38.0°C (100.4°F) or higher. Temperatures below this threshold are not classified as fever, though a child may still feel unwell and symptoms should continue to be monitored.
Is A High Temperature Always Dangerous?
Not necessarily. Many childhood infections cause fever and resolve without complications. The child's overall condition — including behaviour, hydration, breathing and the presence of warning signs — is often more important than the temperature alone. A mildly unwell child with a temperature of 39°C may be of less immediate concern than a lethargic child with a lower temperature.
Why Is Age Important?
Young infants have a higher risk of serious infection because their immune systems are still developing. A fever in a baby under 3 months of age requires prompt medical assessment regardless of the temperature level and the apparent condition of the baby. Infants aged 3 to 6 months with a temperature of 39°C or above should also be assessed by a healthcare professional.
Why Is Hydration Important?
Children with fever can lose fluids through sweating, reduced drinking and vomiting. Mild dehydration is common during fever and is usually manageable at home with frequent small amounts of fluid. Signs of more significant dehydration — such as no urine output, dry mouth, absence of tears, or refusing all fluids — require medical attention.
What Is The Glass Test?
The glass test is a simple method used to check a rash. Press a clear glass firmly against the rash. If the rash fades under pressure, it is likely a blanching rash. If the rash does not fade and remains visible through the glass, this is a non-blanching rash and may require urgent medical assessment, as it can be associated with serious illness.
What Is Neck Stiffness?
Neck stiffness means the child is unable or unwilling to bend the neck forward because of pain or stiffness. It is different from a child simply resisting movement. True neck stiffness in the context of fever may warrant urgent medical assessment.
Can Fever Cause Seizures?
Some children develop febrile seizures during fever, particularly between the ages of 6 months and 5 years. A febrile seizure is usually brief and self-limiting. Any seizure occurring during illness, even if brief, should be discussed with a healthcare professional promptly. A child who has had a febrile seizure previously is at higher risk of recurrence.
When Should I Seek Medical Advice?
Medical advice should be sought whenever warning signs are present, if symptoms worsen, if fever persists beyond 5 days, if you have concerns about the child's condition, or if the child is under 3 months of age. When in doubt, seeking medical assessment is always appropriate.
