Fever in babies and children: what to do and when to worry

What temperature is a fever in a baby?

For babies and children, a fever is 38 °C or higher. A child at 37.5 °C feels warm, but that is not a fever yet.

Fever is not an illness in itself. It is the body fighting an infection, usually a virus, and most fevers settle within 1 to 4 days. The number on the thermometer matters less than how your child is. A toddler at 39 °C who is playing and drinking is less worrying than one at 38.2 °C who is listless and refusing feeds.

Two exceptions, where the number alone is enough to get help:

• Under 3 months, 38 °C or higher — go to the clinic or casualty now, even if your baby seems well.
• 3 to 6 months, 39 °C or higher — get your baby seen the same day.

How to take your child's temperature

A hand on the forehead tells you something is up, but it does not measure. Use a digital thermometer.

Thermometer	Age	Tip
Digital, under the arm	Any age	Easiest at home but the least accurate. Hold the arm down until it beeps.
Digital, in the mouth	From 4 years	Only once your child can keep their mouth closed around it.
Ear	From 6 months	Not reliable in younger babies.
Forehead (temporal)	Any age	Quick; follow the device instructions.

Do not use an old glass mercury thermometer. If it breaks, it releases toxic fumes. Fever strips are also less accurate.

Write down each reading and the time. It is the first thing the nurse or doctor will ask.

What to do at home when your child has a fever

1. Fluids, fluids, fluids. Breastfeed more often. Older children: water, diluted juice, soup. Fever makes children lose water faster.
2. Dress them lightly. One thin layer is enough. Don't bundle them in blankets to "sweat it out", but you don't need to strip them either. A light sheet if they are shivering.
3. Let them rest and check on them regularly, including overnight.
4. Offer food if they want it. Don't force it.
5. Medicine only if they are uncomfortable. The goal is a more comfortable child, not a normal reading.

Paracetamol and ibuprofen

• Paracetamol is the usual first choice. The dose depends on weight and age: follow the pack, or ask the pharmacist or clinic nurse. Use the syringe or measuring cup that comes with the syrup, never a kitchen spoon.
• Paracetamol is not for babies under 2 months unless a health worker tells you to.
• Ibuprofen is not for babies under 3 months or under 5 kg, or for children who are dehydrated (vomiting or diarrhoea). Check with a pharmacist first if your child has asthma.
• Don't alternate the two unless a health professional has advised it.
• Check cold-and-flu syrups: many already contain paracetamol, so you could double the dose by accident.

Fever and malaria: have you travelled?

Most of South Africa is malaria-free, but there is malaria risk in parts of Limpopo, Mpumalanga and KwaZulu-Natal, mainly in summer, and in many neighbouring countries. The NICD notes that malaria symptoms can start up to three weeks after a mosquito bite, and that in children they are very non-specific: fever, poor appetite, vomiting.

• If your child has a fever and has been to a malaria area recently, go to a clinic the same day and tell them where you travelled. Ask for a malaria test (a rapid test or blood smear).
• Children under 5 are at the highest risk of severe malaria, which can become life-threatening quickly.
• Malaria always needs proper treatment from a health worker. Read more in malaria in children.

Febrile seizures: what to do if your child has a fit

Some children, usually between 6 months and 5 or 6 years, have a fit when their temperature rises. Their eyes may roll, the body goes stiff or jerks, and they don't respond. It is terrifying to watch, but most last 2 to 3 minutes.

During the fit:

1. Note the time it starts.
2. Lay your child on the floor or a bed, away from anything hard or sharp.
3. Turn them on their side so saliva or vomit can drain.
4. Don't put anything in their mouth. Children cannot swallow their tongue.
5. Don't hold them down, and don't try to cool them with cold water.

Call an ambulance (10177, or 112 from a cellphone) or go to casualty if it is the first fit, if it lasts more than 5 minutes, if your child struggles to breathe, if only one side of the body is jerking, if there is another fit within 24 hours, or if they stay unusually sleepy for more than an hour afterwards. Even if the fit stops quickly, your child should be checked by a doctor. If you have travelled to a malaria area, say so — a fit with fever can be a sign of severe malaria.

How long should a fever last?

Most viral fevers settle in a few days. Take your child to the clinic or GP if:

• A child under 2 has had a fever for more than 24 hours, or an older child for more than 3 days.
• The fever keeps going above 40 °C.
• They seem to be getting worse, or still seem very unwell after the fever comes down.
• They are not eating, or just "not themselves".

Fever with fast breathing, diarrhoea or a rash always needs to be checked. See danger signs: when to take your child to hospital.

Is it just teething?

Teething can make a baby a little warm, but it does not cause a fever of 38 °C or more. If your baby has a fever and a tooth coming through, treat the fever as a fever. More in teething symptoms and myths.

What to take to the clinic

• Your child's Road to Health Book.
• The temperatures you measured and when.
• Which medicines you gave, how much and at what time.
• Other symptoms: cough, vomiting, diarrhoea, rash, wet nappies, and any recent travel.

If you use Iasora, you can log temperatures and doses as you go and show the list at the clinic.