How to take a temperature
A digital thermometer is the most accurate and easiest to use at home. Ear (tympanic) thermometers are also accurate and quick. Old-style mercury thermometers should no longer be used. A normal temperature is around 36.5–37.5°C; a fever is usually 38°C or above.
Looking after yourself
- Under the arm (digital): put the tip in the armpit, hold the arm gently against the body, and wait for the beep. Suitable for babies and children of any age
- Under the tongue (digital): put the tip under the tongue, close the mouth, and wait for the beep. Suitable for adults and older children
- Ear (tympanic): follow the maker’s instructions — the tip must sit correctly in the ear canal for an accurate reading
- Wait 15 minutes after eating, drinking or exercise before taking an oral or tympanic temperature
- Take two readings if you are unsure
When to get medical help
Use NHS 111 online, call 111, or contact your GP if:
- A baby under 3 months has any fever
- A child aged 3 to 6 months has a fever of 39°C or higher
- A fever is not settling with paracetamol and the person is getting more unwell
Further information
This page provides general information only. It is not a diagnosis and is not a substitute for professional medical advice.