What temperature is considered a fever in adults and children. When should you go to the doctor or emergency room for a fever. How to recognize concerning fever symptoms that require medical attention. What are common causes of fevers in different age groups.

Understanding Fever: Definition and Significance

A fever is generally defined as a body temperature of 100.4°F (38°C) or higher. It’s the body’s natural response to fighting off infections or other health issues. While fevers can be uncomfortable, they’re often a sign that your immune system is working hard to protect you.

But how do you know when a fever is cause for concern? Let’s explore the guidelines for different age groups and situations.

Fever in Adults: When to Seek Medical Care

For adults, most fevers can be managed at home with rest, hydration, and over-the-counter medications. However, certain circumstances warrant medical attention:

• Temperature of 103°F (39.4°C) or higher
• Fever lasting more than three days
• Fever accompanied by severe symptoms like chest pain, difficulty breathing, or confusion
• Fever in someone with a compromised immune system

Is a high fever always dangerous for adults? Not necessarily. The height of the fever doesn’t always correlate with the severity of the illness. However, very high fevers (105°F or 40.6°C and above) can be life-threatening and require immediate emergency care.

Fever in Children: Age-Specific Guidelines

When it comes to children, age plays a crucial role in determining when to seek medical care for a fever:

Infants 0-3 months

Any fever in a newborn or young infant is considered serious. Contact your pediatrician immediately if your baby has a rectal temperature of 100.4°F (38°C) or higher, with or without other symptoms.

Infants 3-6 months

Call your doctor if your baby has a temperature of 100.4°F (38°C) or higher, especially if they show signs of irritability or unusual sleepiness. For temperatures of 102°F (38.9°C) or higher, seek medical attention regardless of other symptoms.

Children 6-24 months

If your child has a temperature of 102°F (38.9°C) or higher for more than a day, accompanied by symptoms like cough, diarrhea, or a rash, it’s time to consult your pediatrician.

Children 2 years and older

For older children, contact your doctor if the fever reaches 100.4°F (38°C) or higher and is accompanied by symptoms such as fatigue, headache, stiff neck, or prolonged vomiting or diarrhea.

How can you accurately measure a child’s temperature? The most reliable method for infants and young children is a rectal thermometer. For older children, oral thermometers are generally accurate when used correctly.

Red Flags: When to Seek Immediate Medical Care

Regardless of age, certain symptoms accompanying a fever require prompt medical attention:

• Seizures
• Severe headache or neck stiffness
• Confusion or altered mental state
• Difficulty breathing or chest pain
• Severe abdominal pain
• Persistent vomiting
• Signs of dehydration (dry mouth, sunken eyes, decreased urination)

Why are these symptoms particularly concerning? They may indicate serious conditions such as meningitis, pneumonia, or sepsis, which require immediate medical intervention.

Fever Management at Home: Do’s and Don’ts

While waiting to see a doctor or managing a mild fever at home, keep these tips in mind:

Do:

• Rest and stay hydrated
• Use over-the-counter fever reducers like acetaminophen or ibuprofen as directed
• Keep the room at a comfortable temperature
• Dress in light, breathable clothing

Don’t:

• Bundle up excessively to “sweat out” the fever
• Use ice baths or alcohol rubs to lower body temperature
• Give aspirin to children or teenagers

Why is it important to avoid these common misconceptions? Bundling up can actually raise body temperature further, while ice baths and alcohol rubs can cause dangerous temperature fluctuations. Aspirin in children and teens can lead to a rare but serious condition called Reye’s syndrome.

Understanding Fever Causes: Beyond Infections

While infections are the most common cause of fevers, other factors can elevate body temperature:

• Certain medications
• Autoimmune disorders
• Heat exhaustion or heat stroke
• Some cancers
• Hormonal imbalances
• Vaccinations (as a normal immune response)

How can you distinguish between infectious and non-infectious causes of fever? Pay attention to accompanying symptoms and recent activities or exposures. A fever with a sore throat and cough is likely due to an infection, while a fever following intense exercise in hot weather could indicate heat exhaustion.

COVID-19 Considerations: When Fever Signals Potential Infection

In the context of the ongoing pandemic, fever takes on additional significance:

• If you have a fever and have been exposed to someone with COVID-19, contact your healthcare provider for guidance on testing and isolation.
• For adults over 65 or those with compromised immune systems, a fever of 101°F (38.3°C) or higher warrants a call to the doctor if COVID-19 exposure is suspected.
• Remember that not all COVID-19 cases present with fever, and not all fevers indicate COVID-19.

Why is it crucial to consider COVID-19 when evaluating a fever? Early identification and proper management of COVID-19 cases can help prevent spread and ensure appropriate care for those at higher risk of complications.

Telemedicine Options: When to Consider a Virtual Visit

With the rise of telemedicine, many fever-related concerns can be addressed through virtual consultations:

• Initial assessment of fever symptoms
• Follow-up for ongoing fevers
• Guidance on home care and when to seek in-person evaluation
• Prescription of necessary medications

How effective are telemedicine consultations for fever management? For many cases, especially those not requiring immediate emergency care, virtual visits can provide quick, convenient, and effective guidance. However, severe symptoms or high-risk situations still warrant in-person evaluation.

Remember, while this guide provides general information, it’s always best to err on the side of caution when it comes to fevers. If you’re unsure whether your situation requires medical attention, don’t hesitate to contact your healthcare provider for personalized advice.

By understanding when to seek care for a fever, you can ensure prompt treatment when necessary while avoiding unnecessary medical visits. Always trust your instincts – if you’re concerned about a fever in yourself or a loved one, it’s better to reach out for professional guidance than to wait and worry.

When to Seek Care for a Fever

A fever (defined as a temperature of 100.4°F or higher) happens when your body is trying to fight off an infection or your immune system becomes activated. The increase in your body temperature signals that something is not quite right with you.

Sometimes a fever comes and goes quickly, other times it lingers, and your temperature fluctuates over time.

Below is a breakdown of when you should contact your doctor or health care provider if you have a fever:

Adults

Numbers that are cause for concern:

• 105°F – Go to the emergency room
• 103°F or higher – Contact your health care provider
• 101°F or higher – If you’re immunocompromised or over 65 years of age, and are concerned that you’ve been exposed to COVID-19, contact your health care provider

Situations that are cause for concern:

• if you have a fever and it doesn’t go down after taking over-the-counter medications, like ibuprofen
• if you’ve been in hot temperatures and develop a fever, it could be a sign of a heat stroke
• if you’ve been in contact with someone who tested positive for COVID-19, you could be at risk for the virus

Call your doctor for medical advice if you experience any of these situations.

Children

Call your child’s pediatrician under the following circumstances:

• 0-3 months – Your child has a temperature of 100.4°F or higher, with or without symptoms
• 3-6 months – Your child has a temperature of 100.4°F or higher, plus irritable behavior/sleepiness OR a temperature of 102°F or higher
• 6-24-months – Your child has a temperature of 102°F for longer than a day AND symptoms such as a rash, cough or diarrhea
• 2+ years – Your child has a temperature of 100.4°F or higher AND symptoms such as a rash, fatigue, headache, stiff neck, prolonged diarrhea or vomiting

Any age:

• Your child has a seizure
• Your child has a temperature of 103°F or higher
• Any fever that starts after your child has been in hot temperatures (could be a sign of heat stroke)
• Your child’s fever doesn’t go down after taking over-the-counter medications, like ibuprofen
• Your child has been in contact with someone who has COVID-19

Next Steps & Resources: 

• To make an appointment with a doctor near you, call 800-822-8905 or visit our physician directory to make an appointment online.
• Register for telemedicine through HMH Care NOW.

The material provided through HealthU is intended to be used as general information only and should not replace the advice of your physician. Always consult your physician for individual care

When to See a Doctor for a Fever

For most adults, having a temperature above 100.4°F is considered a fever. Most fevers can be managed at home and will start to improve within several days. Still, knowing when to speak with a medical provider for a fever can help you get the care you need and avoid complications. 

If you have a fever that won’t go down after several days of rest, have a temperature of 103°F or higher, or experience severe symptoms such as chest pain or difficulty breathing, it’s best to talk to your provider. Read on to learn more.

When to See a Doctor for Fever

Mild fevers can be treated at home. For fevers of 103°F or higher, adults should contact their medical provider or seek emergency care.  

Additional symptoms that warrant more immediate medical attention are:

• A fever that does not improve after three days of rest and home care
• Severe headache
• Severe throat swelling
• Unusual skin rash
• Sensitivity to bright light
• Stiff neck (or pain when you bend your head forward)
• Mental confusion
• Persistent vomiting
• Difficulty breathing
• Chest pain
• Abdominal pain
• Pain when urinating
• Extreme fatigue
• Extreme irritability
• Muscle weakness
• Sensory changes
• Seizure

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What’s Considered a Fever?

One factor that helps distinguish a fever from normal variations in body temperature is age. 

Infant

Any elevated temperature in an infant or child younger than three months old is considered a fever.

Children

A child’s temperature can be read using different types of thermometers. The below temperatures are considered a fever in children three months and older:

• 100°F via oral thermometer
• 100.4°F via rectal thermometer
• 99°F axillary temperature (taken in the armpit)

Adults

Any temperature above 100.4°F is considered a fever in adults.

Common Fever Causes

A fever can be a sign of many conditions. Some of the most common causes of a fever include:

• A viral or bacterial infection
• Medicines (including antibiotics and blood pressure and anti-seizure medications)
• Heat illness
• Cancer
• Autoimmune disease
• Some vaccines

Additional Possible Symptoms

A fever is a symptom of a condition, rather than an illness itself. Depending on the type of illness you have, you may experience other symptoms such as:

• Chills
• Fatigue
• Body aches
• Loss of appetite
• Dehydration
• Irritability

Medical Treatment

Many fevers can be treated at home with rest, fluids, and over-the-counter (OTC) pain relievers. If you need to seek treatment from a medical provider, depending on the underlying cause of your fever, they might recommend one of the following treatments:

• Antibiotics or antivirals
• Other prescription medications
• Intravenous medications
• Fluid replacement

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Fever Risks

Dehydration is a common risk of a fever. That’s why it’s important to rest and stay hydrated by drinking plenty of non-caffeinated liquids (such as water, herbal tea, and electrolyte-based fluids) when you have a fever. 

Additional risks are possible in people with certain medical conditions, including diabetes and cancer. If you’re immunocompromised and have a fever, contact your medical provider for guidance.

How K Health Can Help

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Check your symptoms, explore conditions and treatments, and if needed, text with a healthcare provider in minutes.  

K Health’s AI-powered app is based on 20 years of clinical data.

Frequently Asked Questions

How long is too long to have a fever?

Some fevers last longer than others. If you have a fever that doesn’t begin to improve within three days, contact your medical provider for care.

When should a patient see the doctor for a fever?

Most fevers can be treated at home with rest and drinking plenty of fluids. However, speak with a medical provider if you have: a fever that doesn’t go down in several days, a fever of 103°F or higher, or certain symptoms (including chest pain, shortness of breath, or severe throat swelling). If your infant has any elevated temperature, speak with their pediatrician as soon as possible.

What do you do when a fever won’t go down?

A mild fever may take a few days to go down on its own. In the meantime, get plenty of rest and drink lots of fluids (avoid coffee and other caffeinated beverages). You can also take an over-the-counter (OTC) pain reliever like acetaminophen (Tylenol) or ibuprofen (Motrin or Advil) to help the fever go down. If your fever doesn’t improve within three days, contact your medical provider.

Should you go to the hospital if you have a fever?

You don’t need to go to the hospital for a mild fever. But if you have a fever of 103°F or higher, have a fever that won’t go down after several days, or are experiencing additional symptoms, seek medical treatment.

K Health articles are all written and reviewed by MDs, PhDs, NPs, or PharmDs and are for informational purposes only. This information does not constitute and should not be relied on for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment.

K Health has strict sourcing guidelines and relies on peer-reviewed studies, academic research institutions,
and medical associations. We avoid using tertiary references.

• Fever. (2016).
  https://medlineplus.gov/fever.html

High temperature? When should you see a doctor? — Into-Sana

Causes of fever

An increase in body temperature is most often a protective reaction of the body to infections, it contributes to the death of pathogenic microorganisms, accelerating the response of the immune system. It is for this reason that doctors do not recommend taking antipyretics if the temperature is subfebrile, i.e. does not exceed 38C – you need to give the body the opportunity to “fight” the infection.

At higher numbers, medical temperature control (taking antipyretics) is necessary. This is due to the fact that high temperature significantly increases the load on the cardiovascular and respiratory systems and can contribute to the development of shock-like conditions and convulsive syndrome (especially in children).

Rarely, fever occurs in the absence of inflammatory processes in the body. This can be observed in violation of the processes of thermoregulation in the brain due to its focal lesions, with hormonal disorders (hyperthyroidism), taking certain medications, poisoning with certain substances, neurosis, systemic diseases of the connective tissue, tumor processes, etc.

How to respond to elevated temperature?

• If fever is combined with other symptoms of SARS (runny nose, sore throat, cough, etc. ), self-treatment is possible, the main points of which are bed rest and heavy drinking. When the temperature rises above 38C, it is necessary to take an antipyretic.
• Preservation of elevated temperature on the 5th-7th day of acute respiratory viral infections or a repeated increase in temperature after several days of its normalization is a reason to see a doctor. This situation most often indicates a complication.
• With an increase in body temperature against the background of the absence of symptoms characteristic of SARS, a visit to the doctor is mandatory.

It is necessary to seek medical help immediately (within 24 hours) in the following situations:

• Body temperature 39-40C, headaches, muscle aches, pain when moving the eyes (suspicion of influenza).
• High body temperature against the background of symptoms that are not characteristic of a common cold: shortness of breath, profuse sweating at night, pain when breathing and coughing, pain in the lumbar region, pain when swallowing, etc.
• Increased body temperature after medical manipulations and operations.
• High temperature in a person who returned from another country.

Call an ambulance in the following situations:

• High body temperature, severe headaches, aggravated by bringing the chin to the chest. In this case, it is necessary to exclude meningitis.
• Fever, nausea, vomiting, diarrhea. These symptoms are characteristic of intestinal infections.
• Fever, acute abdominal pain. These signs are characteristic of acute surgical pathology – acute appendicitis, acute cholecystitis, pancreatitis, etc.

Routinely (within a week from the moment of occurrence) it is necessary to consult a general practitioner in case of subfebrile body temperature (37-38C) in the absence of other pronounced symptoms. A condition in which subfebrile body temperature persists for a long time, and the reasons for this increase are unclear, is called a fever of unknown origin. In this situation, it is very important to find the cause. It must be understood that diagnostic search in some of these cases can be difficult.

In all situations of fever, you should contact a general practitioner – an internist. It is this specialist who will assess the situation as a whole and determine the shortest path to recovery.

Be healthy!

First aid procedure for elevated body temperature

Subfebrile temperature (up to 38°C)

1. Undress the child.

2. Wipe with a damp cloth (slightly above room temperature).

3. Do not use antipyretics.

Febrile temperature (above 38°C)

1. Ensure rest, put to bed.

2. Drink plenty of sweet tea, fruit drink.

3. In case of chills, warm the child (warm blanket, hot tea, heating pad to the limbs).

4. Give an antipyretic.

5. At a temperature of 39.5-40°C, the child should not be wrapped.

6. If the temperature is above 40.4°C, give an antipyretic and seek emergency help.

Specialist comments:

The normal temperature is not 36.6°C, as is often believed, but 36.0-37.0°C, in the evening it is slightly higher than in the morning. Body temperature rises with many diseases. The benefits of elevated temperature are a signal of illness, a way to fight pathogens

(many bacteria and viruses stop multiplying at temperatures above 37-38°C), it is a stimulus for the immune response, since a number of protective factors (including interferon) are released only at temperatures above 38°C.

By lowering the fever, we do not affect the cause of the disease, but we can improve the child’s well-being.
Subfebrile temperature (up to 38°C) may occur with overheating, with a viral or bacterial infection. Taking antipyretics in such cases is not worth it if the child’s well-being does not suffer. At a “febrile” temperature (above 38 ° C), vasoconstriction, increased muscle contractions (hence chills, tremors), and in young children convulsions (the so-called “febrile” convulsions) are noted.
When the temperature rises to 39.5-40.0°C, the skin vessels dilate (the skin turns red), such a child should not be wrapped up. Fever is dangerous with spasm of skin vessels – this is malignant hyperthermia.
Symptoms:

temperature above 40.4°C;

Mottled, marbled skin;

extremities cold to the touch;

It is necessary to call an emergency and be sure to give an antipyretic, preferably in a solution inside.

Children should be given antipyretics at temperatures above 38.0 ° C, but if the child does not tolerate high temperatures, worries, cries, or has seizures at elevated temperatures, antipyretics are given at temperatures above 37.5 ° C. After giving an antipyretic, you can not calm down: be sure to consult a doctor (for recovery, you will need to take other drugs).
The main antipyretic recommended for children is PARACETAMOL (acetaminophen). It does not have a pronounced side effect, has an anti-inflammatory and analgesic effect, relieves discomfort.