How do you take a toddler's temperature?

To take a toddler's temperature, use a digital thermometer and, for the most accurate number, a rectal reading; a forehead (temporal artery), ear or armpit reading is a reasonable backup when your child won't cooperate. KidsHealth puts it plainly by age: for kids 6 months to 3 years a rectal temperature is best, while from age 4 an oral reading works if your child can hold the thermometer under the tongue (Taking Your Child's Temperature, accessed November 11, 2026).

That's the rule. The hard part is doing it at 2 a.m. with a hot, sleepy, furious little person on your lap.

Pick the thermometer before you need it

Buy one plain digital thermometer that can be used rectally and keep it only for that. Label it with tape. A second one for armpit or mouth use avoids mix-ups later.

Method	Good for	Watch out for
Rectal	Babies and toddlers, most accurate	Needs a calm hold and lubricant
Temporal artery (forehead scan)	Quick checks, sleeping kids	Sweat or a hat can throw it off
Ear (tympanic)	Kids 6 months and older	Earwax and a crooked angle lower the reading
Armpit (axillary)	Screening only	Reads lower; confirm a high number another way
Oral	Age 4 and up	Wait after a drink or a snack

Skip old glass thermometers; they can break. Strips and pacifier thermometers aren't reliable enough to make a decision on.

Rectal reading, step by step

1. Wash the tip with soap and lukewarm water, then rinse.
2. Put a dab of petroleum jelly on the end.
3. Lay your child belly-down across your lap, or on their back with knees bent toward the chest, like a diaper change.
4. Slide the tip in gently, about half an inch to an inch. Stop if you feel resistance.
5. Hold it there with your fingers, and keep your other hand flat on your child's lower back.
6. Wait for the beep, remove, and read.
7. Clean it again before you put it away.

Talk the whole time. A song with a counted chorus gives your child an end point: "We're done when we get to ten."

Forehead and ear readings

A forehead scanner is the easiest choice for a sleeping toddler. Sweep it across the forehead as the instructions say, in a room that isn't drafty, and with no hat or hair in the way. If the number is borderline, repeat once.

For ear thermometers, gently pull the ear back to straighten the canal before you insert the tip. A child who has just come in from the cold should rest indoors for a few minutes first.

Armpit reading on a toddler who won't hold still

Put the tip high in a dry armpit, fold the arm down across the chest, and hug the elbow in. Read a book together until the beep. Armpit numbers run lower, so if it shows a fever or you are worried, confirm with a rectal or forehead reading.

What the numbers mean

A reading of 100.4°F (38°C) or higher is the line most doctors use for fever. A fever itself is a sign the body is fighting an infection, not an illness on its own. How your child acts matters as much as the digits: a toddler who still plays, drinks and smiles at 102°F is often less worrying than a floppy one at 100.8°F.

Write down three things each time: the time, the number, and the method. Doctors will ask, and it's easy to forget at night.

When to call

Use the age-based guidance on the KidsHealth fever fact sheet (Fever, accessed November 11, 2026) and your doctor's own instructions. In general, call your child's doctor if:

• your baby is younger than 3 months and has any fever;
• the fever keeps going for several days, or your child seems to be getting worse instead of better;
• your child won't drink, has very few wet diapers, or seems unusually sleepy or hard to wake;
• there's a rash, a stiff neck, trouble breathing, or ongoing vomiting.

Call 911 if your child has trouble breathing, turns blue, or can't be woken. The American Academy of Pediatrics' HealthyChildren site walks through each method with pictures and notes how to choose based on age (How to Take a Child's Temperature, accessed November 11, 2026).

Small tricks that help

• Practice when they are well. Let your child "take" a stuffed bear's temperature with the forehead scanner. Familiar tools are less scary.
• Give a job. Your toddler can hold the case, press the start, or announce the beep.
• Avoid a bath first. A warm bath or heavy blanket can raise a reading for a short while; wait 15 to 20 minutes.
• Check medicine timing. If you gave a fever reducer, note when, because it lowers the next reading.
• Don't wake a sleeping child just to check. If they are resting comfortably and breathing easily, sleep helps.

A gentler sick-day routine

Sick days go better with a little predictability: thermometer, drink, rest, a short story, repeat. Some families make a "sick basket" with the thermometer, a cup with a lid, a favorite blanket and a quiet book. If your child is facing a longer stretch of care, a personalized last-treatment book can tell the story of getting through it in their own family's words.

Related reading

• Hospital stories and books
• How to give a toddler liquid medicine
• Staying overnight in the hospital
• How to Teach a Toddler to Blow Their Nose

FAQ

Is a forehead thermometer accurate enough for a toddler?

It is fine for quick checks. If it shows a fever in a young child, or the number doesn't match how your child looks, confirm with a rectal reading.

Should I add a degree to an armpit reading?

Don't adjust the number yourself. Tell the doctor the reading and that it was taken under the arm.

Can I use the same thermometer for mouth and bottom?

Keep separate ones and label them. It's simpler and more hygienic.