High Fever in Infants

High Fever in Infants: A Guide for Parents

High temperature (fever) in a child is one of the biggest fears for parents. A hot forehead, lethargy, and a baby's crying trigger panic. However, it is important to understand that fever is not a disease, but a protective reaction of the body to infection. It indicates that your child's immune system is actively fighting pathogens. The main task for parents is not to "bring down" the temperature at any cost, but to ease the child's condition and know when it is necessary to seek medical attention urgently.

What is considered a high temperature?

Normal body temperature in an infant can vary. Fever is usually defined when the rectal temperature reaches 38°C or higher. Measuring temperature rectally is the "gold standard" for children in the first year of life.

Causes of high temperature

In the overwhelming majority of cases, fever is caused by an infection:

• Viral infections (URIs): This is the most common cause. Usually accompanied by runny nose, cough or sore throat.
• Bacterial infections: Such as middle ear infection (otitis media), urinary tract infection, pneumonia.
• Reaction to vaccination: A mild temperature rise for 1–2 days after a shot is a normal immune response. More details are in the article about the vaccination schedule.
• Overheating: Infants can easily overheat if they are dressed too warmly.

When is a high temperature dangerous?

The level of danger depends less on the number on the thermometer and more on the child's age and overall condition. Seek medical help or call emergency services immediately if:

• The child is under 3 months old and the temperature is 38°C or higher. At this age any fever requires a doctor's examination.
• Temperature exceeds 40°C.
• Seizures occur in the context of fever seizures.
• The child appears very lethargic (lethargic), difficult to wake.
• Signs of dehydration are present (dry diapers, crying without tears).

How and when to safely reduce fever is explained in detail in our blog "Fever in Infants: When to Reduce It and How to Do It Safely".