How to Take a Child's Temperature While They Sleep

The short answer: use a non-contact forehead thermometer. Make sure the forehead is uncovered and has not been pressed into the pillow, hold the thermometer 1 to 5 cm from the centre of the forehead with the sound off, and read the result on the screen. If the reading is high, wait a few minutes and check again before deciding anything. You usually do not need to wake a sleeping child to give fever medicine.

Which thermometer works on a sleeping child?

The American Academy of Pediatrics lists the main methods and the ages they suit.¹ Applied to a child who is asleep:

Method	On a sleeping child
Forehead, non-contact	Best option. Can be used at any age and never touches the skin.
Forehead, contact	Works, but you have to touch and slide across the skin.
Armpit	Possible, but you have to move their arm and hold it still. The least accurate method.
Ear	From 6 months only, and hard to position on a child lying on their side.
Oral	Not suitable. Needs a cooperative child aged 4 or older.
Rectal	Most reliable for babies under 3 months. Use it to confirm a high forehead reading in a young baby.

Step by step

1. Keep the thermometer in their room. An infrared thermometer is most accurate when it has been at room temperature for about 20 minutes. Do not carry it in your hand or pocket beforehand.
2. Turn the sound off. On TempBuddy, Silent Mode mutes the scan tone, and the number appears on your phone screen instead of being announced to the room. Turn the screen brightness down.
3. Look at the forehead. It should be uncovered and dry. Gently move hair aside. If they have been lying with their forehead in the pillow, or under a hat, that patch of skin will read warm.
4. Loosen heavy covers first. The NHS notes that a child who has just been wrapped in a blanket or had a bath may read higher for a short time. Pull the blanket back a little and wait a few minutes.²
5. Aim and hold. Point the sensor at the centre of the forehead, 1 to 5 cm (0.4 to 2 in) away, without touching. Hold steady for the half second the reading takes. If they stir, TempBuddy's Peak Mode keeps reading while they move and locks in the most reliable result.
6. Check it twice if it is high. Wait a few minutes and repeat. A single unusually high or low reading is worth confirming.
7. Write it down. Note the time and the reading. TempBuddy saves it to the right family member automatically, so you can see in the morning how the night went.

Should you wake them to give medicine?

Usually not. Seattle Children's Hospital advises: "Don't wake your child up to give them fever medicine."³ Rest helps, and most of the time fever itself is not harmful. If they wake up uncomfortable, that is the time to think about a dose. Check the label or ask a pharmacist for the right amount for their age and weight, and log the time so the next dose is not given too early.

The exceptions are below. A fever in a very young baby, or a child who is hard to wake, is not something to sleep on.

When to wake them and call a doctor

• A baby under 3 months with a temperature of 100.4 °F (38 °C) or higher.^1,2
• A baby of 3 to 6 months at 102.2 °F (39 °C) or higher.²
• A fever that rises above 104 °F (40 °C) repeatedly, at any age.¹
• A child who is unusually drowsy or hard to wake, looks very ill, or is breathing fast or with difficulty.
• A seizure, a stiff neck, a severe headache, an unexplained rash, or repeated vomiting or diarrhoea.

If your child is very hard to wake, struggles to breathe or has a seizure, call 911 or your local emergency number. And if you are worried for any other reason, call your doctor anyway. You know your child.

Why parents use TempBuddy at night

• No contact: it never touches the skin.
• Silent Mode: no beep, and the result is on your screen.
• Half a second: less time hovering over a light sleeper.
• Colour cue: green, amber or red, readable without your glasses.
• Saved automatically with the time, to the right child, with reminders for the next recheck.

It plugs into iPhone 15 and newer, and Android phones with USB-C. See TempBuddy.

Keep reading

• The best thermometer for grandparents and elderly parents
• How to keep a family fever log your doctor can use
• Best contactless thermometer for families: what to look for

Sources

1. American Academy of Pediatrics, HealthyChildren.org: How to Take a Child's Temperature.
2. NHS: High temperature (fever) in children.
3. Seattle Children's Hospital: Fever.
4. TempBuddy ZTP-800 Full User Manual, on our support page.