Something’s not right with your little one. While usually a good eater, your baby won’t take a bottle or breastfeed. They have no interest in their favorite toy even when you make it dance before their eyes. And when you reach out to console them, their skin is hot to the touch. Is it a fever?

As a parent, you know when your baby isn’t acting normal. And if you think your baby has a fever, it’s understandable to be a little nervous. You’d rather feel sick yourself than have your little one be under the weather.

Try not to worry. Every baby will likely have a fever at some point in their young lives, and most fevers are mild and can be treated at home.

Still, it’s important to know the signs of fever in babies, how to take their temperature, what’s considered a fever, and when to call your baby’s doctor or seek immediate care for fever symptoms.

Common signs of a fever in babies

So, what are signs that baby may have a fever? These are some of the first cues:

• Baby’s forehead or neck feels warm when you use the back of your hand to check (their body temperature should be about the same as yours).
  • If your child is acting normal, but their temperature is elevated, don’t worry just yet. Sometimes little ones can run quick fevers but not be sick. So, monitor them for any symptoms listed below.
• Baby doesn’t look like themselves. Maybe they’re shivering, sweating or have flushed red cheeks.
• Baby is acting differently. For example, they may:
  • Seem weaker or sleepier than usual
  • Be extra fussy
  • Have a decreased appetite or poor eating
  • Show no interest in playing
  • Have trouble sleeping
• Baby isn’t peeing like normal. When you change their diaper, you notice changes in urine color, odor or amount.
• Baby is vomiting.

Causes of fever in babies

A fever is not an illness and is often, but not always, a sign that baby’s immune system is fighting something. Here are some of the most common reasons for fevers:

• A cold or flu
• Ear infection
• Urinary infection
• Pneumonia
• Hand, foot and mouth disease
• Bacterial infection caused by a severe diaper rash
• A mild side effect of recent vaccinations
• They’re overheated

How to take your baby’s temperature

If your baby is showing any signs of a fever, take their temperature. The best way to do this – and the thermometer to use – depends on your baby’s age.

Finding the right thermometer

The best temperature readings come from direct contact with your baby. So, for the first six months of their life, you should always use a digital thermometer.

You’ve probably used a digital thermometer to take your own temperature by placing it under your tongue. But you’ll take your baby’s temperature by placing the thermometer in either their armpit or rectum.

So, look for one that is labeled for rectal use. You may also find an all-in-one thermometer that can be used orally, rectally or in their armpit. If you opt for an all-in-one thermometer for rectal use, make sure to label it. The same thermometer should never be used for both rectal and oral temperatures.

Once your baby is over 6 months old, you can use remote thermometers for the forehead and ear canal to take their temperature. Thermometers not recommended for any age baby include plastic strip thermometers, pacifier thermometers and smartphone temperature apps.

How to take your baby’s temperature rectally

A rectal temp is considered the gold standard for accurately knowing an infant’s temperature until they’re over 6 months old. Here’s how to get an accurate reading:

Using a digital thermometer to measure rectal temperature

1. Clean the digital thermometer by washing it with soap and water, or wiping with rubbing alcohol.
2. Lay your baby down either on their back or belly with legs bent toward their chest.
3. Apply petroleum jelly to the metal tip of the thermometer and gently glide it into the rectal opening – usually about half an inch, but follow your specific thermometer’s instructions carefully.
4. Turn on the thermometer.
5. Hold the thermometer in place until it beeps – usually about two minutes.
6. Slide out the thermometer.
7. Make note of the temperature.
8. Clean the thermometer before storing.

If you’re uncomfortable taking your baby’s temperature rectally, you can call a nurse line and ask to be walked through the process over the phone (both your clinic and health plan likely offer this kind of service).

How to take your baby’s temperature under their arm

Taking your baby’s temperature under their arm is very simple. Just know that this type of reading is less accurate, and can be affected by the amount of clothing your baby is wearing and the temperature in the room.

Using a digital thermometer to measure armpit temperature

1. Remove baby’s clothes so their chest is bare.
2. Place the digital thermometer in one of their armpits.
3. Fold their arm over the thermometer.
4. Turn on the thermometer.
5. Hold their arm in place until the thermometer beeps, which usually happens in less than two minutes.
6. Remove the thermometer.
7. Make note of the temperature, adding one degree to the reading.

How to take your baby’s temperature with a remote forehead thermometer

If your baby is older than 6 months, a temporal artery thermometer (TAT) can be an easy way to measure your baby’s forehead temperature from a distance.

A TAT uses infrared light to read the temperature of the temporal artery, which is located in your baby’s forehead.

The benefit of a TAT is that it can quickly record a temperature, and your little one won’t need to hold still for a whole minute or two. But readings can be less accurate than digital thermometers.

Using a temporal artery thermometer

1. Make sure baby’s forehead is clean and dry.
2. Hold thermometer in front of the baby’s forehead at the correct distance. (This distance is different for every thermometer, so make sure to follow the directions for your specific model.)
3. Hold down the button and wait for the thermometer to beep. This shouldn’t take more than a couple seconds.
4. Make note of the temperature.

How to take baby’s temperature with a remote in-ear thermometer

Another option for babies 6 months and older is an in-ear thermometer. Also called a tympanic thermometer, this type of thermometer measures the temperature of the ear drum using infrared light.

A tympanic thermometer is similar to a TAT but has a small cone-shaped probe to use in the ear canal. Some TATs have probe attachments that allow them to be used in-ear.

Using a tympanic thermometer

1. Check the inside of baby’s ear to make sure it’s clean.
2. Clean the tip of the probe with rubbing alcohol.
3. Gently tug your baby’s ear straight back to make room for the probe.
4. Gently ease the probe into the ear canal.
5. Press the button and hold thermometer in place until it flashes or beeps. This is usually just a second or two.
6. Remove thermometer.
7. Take note of the temperature.

If used correctly, in-ear thermometers can provide reliable temperature readings in older babies. But they aren’t as accurate if your baby has earwax buildup or a small, curved ear canal.

What is a normal temperature for a baby?

Some changes in your baby’s temperature are completely normal. A baby’s temperature naturally goes up throughout the day or when lying in a warm blanket. Likewise, their temperature may go down on colder days or after spending time in the bath.

Generally, a normal temperature for a baby is between 97 degrees and 100.3 degrees Fahrenheit. If something’s off with your baby’s internal systems, you’ll typically see bigger spikes or drops in temperatures that don’t go away on their own, and the baby will start to act sick.

Baby temperature chart

Where do low-grade fevers fall in the temperature chart?

Low-grade fevers or mild fevers in babies are often described by several different ranges. Some people may consider anything between 98.6 degrees and 100.3 degrees a mild fever. Others may think temperatures between 99.5 degrees and 102.2 degrees indicate a mild fever.

Among most doctors, a mild or low-grade fever in babies is between 100 and 102 degrees. But, unless your baby’s behavior has changed or there are other concerning symptoms, no treatment may be necessary.

Baby fever treatment based on age

If baby has a fever, does that mean you should immediately call your baby’s doctor? Not necessarily. A lot depends on your baby’s age and the type of fever they have. Here’s a quick rundown of treatment, depending on your baby’s age.

If your baby is less than 3 months old

What’s considered a fever in a newborn? While a fever is a fever, regardless of age, doctors want to see younger babies with fevers sooner. That’s because young babies can get very sick, very quickly and it’s important to identify the cause and start treatment as soon as possible.

So, call your baby’s doctor or nurse line if their temperature is 100.4 degrees or higher. If your baby is less than two months old, the doctor will want to see baby as soon as possible. Also, anytime your baby is acting ill – whether a fever is present or not – call in.

You can help your baby feel comfortable at home by keeping them in lightweight clothing and not over-bundling with blankets. Also, try to increase the frequency of breastfeeding or bottle feeding to prevent dehydration.

Watch out for low body temp in infants

What should you do if your baby’s temperature is low? If your baby is cold, warm them up! Cuddling under a warm blanket or an extra layer of clothing are good choices to warm up your baby. But you should call your doctor if their temperature drops below 97 degrees.

Small babies are less able to regulate their body temperature. In other words, sometimes when babies get cold, they stay cold or get even colder.

If a baby’s temp stays low for a long period of time, it can affect their metabolism and breathing, as well as increase their overall risk of serious complications. So if your baby is cold to the touch, or has blue lips or fingers, take their temperature. If it’s low, give your baby’s doctor a call.

If your baby is 3–6 months

If your baby has a mild fever, but they’re acting normal, you may not need to see the doctor. Usually the best course of action is keeping baby comfortable, dressing them in light clothing and making sure they are getting enough to drink.

But if your baby’s temperature is above 102 degrees, definitely call. When you talk to the nurse line or doctor, they will want to know if your baby is not eating or sleeping well, or if they seem less comfortable than normal. Using this information, the nurse or doctor will provide a recommendation on what to do next, which may include giving your child a dose of Tylenol to help with comfort.

A mild fever can actually be a good thing because it shows that baby’s immune system is working the way it should. Making sure that baby is getting enough liquids will help keep them comfortable – and hydrated – so continue with frequent feedings.

And as a heads up, you’ll probably start to see more crying, crankiness and mild fevers when your baby starts teething, which usually happens at around 6 months. Teething time can be a challenge, so try out different ways to make your baby more comfortable and teething easier, including a solid teething ring, a wet washcloth or a refrigerated pacifier.

If your baby is 6–24 months

If your baby is drinking plenty of fluids, still sleeping well and continuing to play, there may be no need to treat a mild fever. You probably will only need to come in if your little one has a temp of 102 degrees or higher that lasts longer than a day. Give the nurse line a call if you’d like help determining if you should schedule an appointment. They can also recommend which medicines to use and how much, if necessary.

When to call your baby’s doctor or seek care for a fever

Here are some guidelines for when to seek care based on your baby’s age and temperature. But if you’re concerned about your baby and their temperature is normal, call anyway. The pediatric team at HealthPartners is always here for you and your little one.

Call your baby’s doctor or nurse line within 24 hours if:

• Your baby is 2 to 3 months old and has a temperature of 100.4 degrees or higher, or a temperature lower than 97 degrees.
• Your baby is 3 to 6 months old and has a temperature of 102 degrees or higher.
• Your baby is 6 to 24 months old and has a temperature of 102 degrees or higher that lasts longer than a day.

Call your baby’s doctor or go to urgent care or the emergency room right away if:

• Baby is under 2 months old and has a fever.
• Baby is unvaccinated and has a fever.
• Baby is nonstop crying or cries when touched or moved.
• Baby is having difficulty breathing.
• Baby is struggling to swallow fluids.
• Baby is shaking or has chills that last more than 30 minutes.
• Baby keeps vomiting.
• Baby has an unusual skin rash that worsens.
• Baby stops peeing.

Call 911 for immediate emergency care if:

• Baby isn’t moving.
• Baby can’t wake up.
• Baby has severe trouble breathing such as struggling for breath or can barely cry or speak.
• Baby has purple or blood-colored spots or dots on their skin.

Nervous about your baby’s fever? We can help.

If you’re not sure if you should be concerned about your baby’s temperature, call us. We’re here to help.

HealthPartners members and patients can call 800-551-0859. Park Nicollet patients can call their clinic directly during regular business hours, or 952-993-4665 if it’s after hours. For questions and advice on new baby care, you can also call our 24/7 BabyLine at 612-333-2229.