How do I take someone's temperature?

You can take someone's temperature quickly and easily using a thermometer. Make sure the thermometer is clean and read the manufacturer's instructions first.

Children

If you're taking a child's temperature, stay with them during the reading and put the thermometer away afterwards so they don't play with it. Read more information about taking a child's temperature.

Choosing a thermometer

You can buy a thermometer from your local pharmacy. Several different types are available. A member of staff can advise you about which thermometer will best suit your needs.  

Digital thermometers

Digital thermometers can be used to take someone's temperature from either their armpit or their mouth. However, for children under five, take their temperature from their armpit because they may bite the thermometer if it is placed in their mouth.

When taking an armpit reading:

  • put the thermometer directly against the skin under the arm
  • hold the arm gently against the body

Check the manufacturer's instructions to find out how long you need to leave the thermometer in place.  

For adults, digital thermometers are an accurate and easy way to take a temperature. Read the manufacturer's instructions to find out:

  • how to place the thermometer correctly in the mouth
  • how long the reading will take 

Ear thermometers

Ear thermometers are quick and easy to use, but they are expensive. Read the manufacturer's instructions to find out how to place the thermometer in the ear and how long the reading will take.

The reading may not be accurate if the thermometer is not correctly placed in the ear. 

Strip-type thermometers

Strip-type thermometers, which you hold on your child's forehead, are not an accurate way of taking their temperature. They show the temperature of the skin, not the body.

Mercury-in-glass thermometers

Mercury-in-glass thermometers are no longer used in hospitals and are not available to buy. They can break, releasing small shards of glass and highly poisonous mercury. You should not use mercury thermometers. If your child is exposed to mercury, seek medical advice quickly by calling NHS 111.

What's a normal temperature?

A normal temperature is around 37ºC (98.6ºF), although it depends on:

  • the person
  • their age
  • what they've been doing
  • the time of day
  • which part of the body you take the temperature from

A fever (high temperature) is a temperature of 38ºC (100.4ºF) or over. However, in children under five, a fever is a temperature of more than 37.5ºC (99.5ºF). For more information, see What is a fever (high temperature) in children?

If someone has a fever and you need medical advice, you can:

Read the answers to more questions about accidents, first aid and treatments

Further information:

Media last reviewed: 13/02/2013

Next review due: 13/02/2015

Page last reviewed: 11/07/2012

Next review due: 10/07/2014