How do I take my newborn's temperature?
Use a digital thermometer according to its instructions. Two NHS pages give different urgent care routes for a baby under three months with a temperature of 38 degrees Celsius or higher.
The short answer
Use a digital thermometer under your baby’s armpit. The NHS says a baby under three months with a temperature of 38 degrees Celsius or higher needs urgent help: call 999 or go to A&E. Outside the UK, use your local emergency number.
Use a digital thermometer
The NHS recommends a digital thermometer for a fast, accurate reading. For a child under five, it says to place the thermometer in the armpit, then hold the baby’s arm gently but firmly against their body for the time stated in the manufacturer’s instructions.
A reading can be affected by a warm room, heavy clothing, a blanket, activity or a recent bath. The NHS advises letting a child cool for a few minutes, without becoming cold or shivery, before checking again when one of these may have affected the reading.
Don’t rely on touch alone
Feeling a baby’s back or chest may alert you that they seem hotter than usual, but a thermometer gives a reading. Follow the instructions for your device. The NHS says forehead strip thermometers measure skin temperature and aren’t an accurate way to take a baby’s temperature.
If you can’t get a reading, are unsure how to use the device or your baby seems unwell, contact a health professional. A temperature log can help you describe the number and time, but it can’t explain the cause or replace a check.
When to get urgent help
The newest NHS urgent help page says to call 999 or go to A&E if a baby under three months has a temperature of 38 degrees Celsius or higher. An older NHS page suggested an urgent GP appointment or NHS 111 instead. Go with the newer advice and get help straight away.
If your baby seems seriously unwell, call for help even if their temperature is normal. Don’t wait to see if it changes.
Sources and further reading
- NHS guidance on taking a baby’s temperature
- NHS urgent medical help for babies and children under five
Sources checked 12 October 2026. This page doesn’t replace advice from your own doctor.