Fever in Children: How High Is Dangerous?
At what temperature does fever in children become dangerous, how can you bring it down at home, and which signs mean you should go to the emergency department without delay? Signs of fever, using fever reducers and the questions parents ask most.
Fever is the most common reason families see a pediatrician. Yet fever itself is not an illness; it is a sign that the body is fighting an infection. What really matters is not the number on the thermometer, but how the child looks overall.
What temperature counts as a fever?
A temperature of 38 °C or higher measured under the arm (axillary) is considered a fever. Ear or forehead thermometers are practical but less reliable; if in doubt, repeat the measurement under the arm.
The most important rule: it depends on age
A fever of 38 °C or higher in a baby younger than 3 months is not something to watch at home. Because infections can progress quickly at this age, see a doctor without delay instead of giving a fever reducer and waiting.
In children older than 3 months, the temperature alone is not a reliable guide. A child with a 39 °C fever who is playing and drinking is often doing better than a child with a 38 °C fever who cannot be woken and is limp and weak.
Signs that mean you should seek care without delay
- Cannot be woken, extreme weakness, constantly drowsy
- Fast or labored breathing, skin pulling in between the ribs, turning blue
- Refusing to drink, clearly less urine (fewer wet diapers), dry mouth
- Red-purple spots on the skin that do not fade when pressed
- Having a seizure (fit)
- Severe headache, stiff neck, discomfort with light
- Fever lasting longer than 3 days, or coming back after it had settled
- In babies a few months old, irritability or moaning-type crying
What to do at home
The aim of bringing a fever down is to make the child comfortable, not to get the thermometer down to a certain number. If the child is comfortable and drinking, medicine is not necessary, even with a fever of 38.5 °C.
- Give plenty of fluids. Fluid loss increases during a fever. Water, breast milk, ayran (a thin yogurt drink) or diluted fruit juice are suitable.
- Dress the child in light clothing. Heavy covers and tight wrapping raise the temperature.
- Keep the room at a normal temperature; do not overheat it.
- Give the fever reducer based on the child's current weight. A sibling's dose or doses measured with a household spoon can be wrong; use the measuring device that comes with the medicine.
What you should never do
- Do not give aspirin (acetylsalicylic acid). In children, it is linked to Reye syndrome, a serious condition that affects the liver and brain.
- Do not rub the child with alcohol, cologne or vinegar. It does not work and can be absorbed through the skin and cause poisoning.
- Do not sponge with ice-cold water. It can cause shivering and push the temperature even higher. If the child is uncomfortable, sponging with lukewarm water is preferred.
- Do not start antibiotics on your own. Most childhood fevers are caused by viruses; antibiotics do not work in these cases.
About fever reducers
The two most commonly used medicines are paracetamol (acetaminophen) and ibuprofen. Ibuprofen is not used in babies younger than 6 months without a doctor's advice. Alternating the two medicines is not routinely recommended; it can lead to dosing mix-ups and taking too much medicine. The choice of medicine and dose is decided by the doctor according to the child's age, weight and any other illnesses.
Febrile seizures (seizures with fever)
A seizure caused by fever can occur in about 2-5% of children between 6 months and 5 years of age. It is extremely frightening the first time, but most stop on their own within a few minutes and leave no lasting damage.
What to do during a seizure:
- Lay the child on a flat surface, on their side.
- Do not put anything in their mouth — including fingers, a spoon or water.
- Do not try to force their movements to stop.
- Keep track of how long it lasts.
- If it lasts longer than 5 minutes, call 112. Every child who has a first seizure must be assessed by a doctor.
Fever-reducing medicines have not been shown to prevent seizures; for this reason, giving fever reducers continuously "to prevent a seizure" is not recommended.
Two common questions
"If the fever is high, does it mean the illness is serious?" No. There is no direct link between how high the fever is and how serious the illness is. A simple virus can cause a 40 °C fever, while a serious infection can come with a low fever. That is why the child's overall condition is what counts.
"If I don't bring the fever down, will it harm the brain?" Fevers caused by infection do not rise on their own to levels that would cause brain damage. What causes harm is not the fever itself, but the underlying illness.
Sources
- NICE — Fever in under 5s: assessment and initial management (NG143). nice.org.uk
- American Academy of Pediatrics — Fever and Your Baby / HealthyChildren.org. healthychildren.org
- American Academy of Pediatrics — Clinical Practice Guideline: Febrile Seizures. publications.aap.org
- Turkish Ministry of Health (T.C. Sağlık Bakanlığı) — Akılcı İlaç Kullanımı (appropriate medicine use) information, in Turkish. saglik.gov.tr