A fever is a high temperature. As a general rule, a temperature of 38C (100.4F) or above is a fever.
As a parent it can be extremely worrying if your child has a high temperature. But it's very common and often clears up by itself.
Most fevers are caused by infections. When the body temperature goes up it makes it harder for the virus or bacteria to survive. They are also a common side effect of vaccinations.
If your child is well, playful, eating and drinking there is usually no need to see a doctor.
Has other signs of being unwell, such as persistent vomiting, refusal to feed, floppiness or drowsiness, breathlessness, rashes or is having a seizure.
If your child has a fever, it's important to keep them hydrated by giving them plenty of cool water to drink.
Babies should be given plenty of liquids, such as breast milk or formula. Even if your child isn't thirsty, try to get them to drink little and often to keep their fluid levels up.
If the environment is warm, you could help to your child to stay at a comfortable temperature by covering them with a lightweight sheet or opening a window.
However, they should still be appropriately dressed for their surroundings and sponging your child with cool water is no longer recommended to reduce a fever.
If your child is distressed then some child paracetamol or ibuprofen can help bring down their temperature.