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Is 101 fever high: How high a fever is too high?

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:


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.


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

100, 101 or 102 Degree Fever? Adult Guide to High Temperatures

A fever is defined as a body temperature above 100.4°F (38.3°C).  The normal oral temperature for a resting, healthy adult is about 98.6°F (37°C). However, what is considered a “normal” body temperature can vary by one degree based on age, race, and other factors.  For example,  an individual who is over 70 years old may have a lower normal temp at 96.8°F (36°C). Furthermore, a person’s temperature may increase or decrease by 1 to 2 degrees throughout the day depending on time of day, activity level, the environment (hot or cold), hydration status, or even medications that he/she may be taking.

In general, a fever indicates the presence of inflammation.  It may occur in the presence of an underlying illness such as an infection, malignancy, or even bodily injury.  It may also be associated with certain autoimmune diseases.  Less commonly, certain medications are associated with fevers.  A fever itself, however, is merely a symptom, and not a disease.

A brain structure called the hypothalamus sets body temperature, and produces a fever response.  It can raise the body’s internal thermostat to combat illnesses.  In this way, the hypothalamus responds to an infection or inflammation by helping the immune system to defeat the offending agent.  Although it may not be comfortable, a temperature of up to 102°F is generally safe in adults. In fact, most healthy adults can even tolerate a fever as high as 103°F to 104°F for short periods of time without having any significant problems.  The body temperature usually returns to normal once the illness resolves.  Click here for a list of fever symptoms in adults.

Page Contents

What is the difference Between Fever and Hyperthermia?Ranges in Body TemperaturesSymptoms of FeverHow to Take Your Temperature – Fever in AdultsHow to Take Your Temperature – Fever in ChildrenHow to Take Your Temperature – ThermometersMercury ThermometerDigital ThermometersFever in adults – How to Treat a FeverWhen to Call Your DoctorTreatment of Hyperthermia Fever in Newborns and Children

What is the difference Between Fever and Hyperthermia?

The terms fever and hyperthermia are commonly confused, and are completely different entities. Hyperthermia is defined as a sustained body temperature above 104°F (40°C), and is just another word for overheating.   The hypothalamus functions normally, but the body’s ability to get rid of heat is impaired.  This most commonly occurs during exposure to extreme heat such as when exercising in hot outdoor temperatures.   Insufficient hydration can also increase the risk of hyperthermia.  

Ranges in Body Temperatures

While there are numerous definitions of fever or pyrexia, the CDC defines a fever as a temperature above 100.4°F (38°C). However, it is important to keep in mind that, in the elderly, temperatures below 100.4 may also be indicative of a fever.  The hypothalamus of these individuals is less able to elevate their body temperatures.  It is, therefore, important to take note of any additional concerning symptoms.

Here are some other definitions related to body temperature: 

  • Normal: temperatures between 97.7°F (36.5°C) and 99°F (37. 2°C)
  • Low-grade fever: temperatures between 99°F (37.2°C) and 100.4°F (38°C)
  • Fever (pyrexia): temperatures between 100.4°F (38°C) and 105.8°F (41°C)
  • Hyperpyrexia: temperatures between 105.8°F (41°C) and 109.4°F (43°C)
  • Temperatures above 109.4°F (43°C) are usually fatal

Symptoms of Fever

Fevers can cause a wide variety symptoms. The most common ones are listed below:

    1. Muscle aches
    2. Headaches
    3. Irritability
    4. Chills
    5. Loss of appetite
    6. Sweating
    7. Generalized weakness

Click here for a list of fever symptoms in adults.

How to Take Your Temperature – Fever in Adults

Adults should use a digital thermometer, placing the tip under the tongue.  Forehead (temporal artery) measurements are also fairly accurate.  Readings taken with an ear (tympanic membrane) thermometer can vary, and may be inaccurate if there is an ear infection.  When readings from both ears are compared, the numbers may differ.

Taking a temperature under the armpit is not very accurate, but can be a quick way to take one’s temperature. When doing so, add one degree to know the true core body temperature.

How to Take Your Temperature – Fever in Children

When taking a child’s temperature, the digital thermometer tip should be placed under the tongue if age four or older. Tympanic membrane and forehead models may be used over the age of six months, but expect some variation in readings when using ear thermometers. 

In infants, the most accurate way to take a temperature is rectally.  A fever in infants under age three months can be a sign of a life threatening infection, so taking the temperature correctly is crucial.   

How to Take Your Temperature – Thermometers

Wash your hands with soap and warm water prior to using any thermometer. 

Mercury Thermometer

Because digital thermometers have become very affordable, the use of old glass mercury thermometers should be avoided.

Mercury is poisonous and is released when a glass thermometer breaks.  Furthermore, because it takes some skill to get a proper temperature reading, so they are not as accurate as the latest digital thermometers.

What to Do if a Mercury Thermometer Breaks.

Digital Thermometers

Digital thermometers are affordable, and readily available nowadays.  Because of the digital number displays, they are easy to read.  Click here for thermometer recommendations.

Before each use, make sure that the thermometer is clean and turned on. Again, wash your hands with soap and warm water to prevent the spread of infection. Follow the manufacturer’s instructions regarding appropriate usage for an accurate temperature reading, and always clean the thermometer before putting it away.

Fever in adults – How to Treat a Fever

  • Stay hydrated.  In response to a fever, the body sweats in an effort to cool off.  Since sweat contains water, it must be replaced.  Water is the best option for rehydration in most cases.  If there are fluid losses due to vomiting or diarrhea, electrolyte replacement beverages may be ideal.
  • Regularly take and record your temperatures.  If taking medication to lower the fever, it should drop within an hour.
  • Monitor associated symptoms.  Take your temperature more frequently if your symptoms change (e.g. if you start vomiting)
  • Antipyretics.  For fevers that are uncomfortable (e.g. associated muscle aches, headaches) you can take acetaminophen or ibuprofen. These medications help to reset your body’s thermostat, and lower the temperature.
  • Do not give aspirin or products that contain it to children or teens under the age of 20. This can potentially cause Reye syndrome, a potentially dangerous condition
  • Watch for signs of dehydration.  This can occur if the fever causes you to sweat excessively, or is associated with vomiting or diarrhea.  Signs of dehydration include thirst, dry skin, dry mouth, chills, feeling tired or weak, and dark-colored urine.
  • Other fever remedies for adults.

When to Call Your Doctor

  • Fevers above 103°F 
  • Persistent fever.  Many viral illnesses, especially the flu, cause fevers of 102°F or higher for three to four days.  If associated with such illnesses, it is worth seeing a doctor for any fever that lasts longer.  For fevers that develop with no other symptoms, one should see a doctor if it lasts more than 48 hours.
  • If your fever is associated with: 
    • Shortness of breath, chest pain 
    • Severe cough 
    • Seizures 
    • Confusion 
    • Persistent vomiting or diarrhea 
    • Severe headache 
    • Skin rash
    • Sensitivity to bright light and/or neck stiffness (could indicate meningitis – an infection of the lining of the brain, spinal cord)
    • Severe abdominal pain (could indicate diverticulitis, appendicitis, or other abdominal disorder)
    • Pain with urination (could indicate a urinary tract infection)

Treatment of Hyperthermia 

Hyperthermia is different from just a fever.   It is more dangerous.  The body becomes overheated and loses its ability to thermoregulate.  If measures are not taken to cool down the body, it can lead to organ damage and death.  When the body’s temperature rises above 104°F and is associated with other symptoms, it is called heatstroke.  This is a medical emergency and should be treated as such. Call 911. Symptoms may include:

  • Confusion 
  • Vomiting 
  • Slurred speech
  • Racing heart
  • Rapid breathing 
  • Loss of consciousness

Before these symptoms occur, moving indoors to an air-conditioned room can gradually lower the core body temperature to a safe range.  Drinking plenty of cool fluids is also helpful.

Fever in Newborns and Children

Fevers in newborns and children are often treated differently than those seen in adults. Please refer to the following links:

Fever in newborns can be serious, and should not be ignored.

Fever in Young Children (Toddlers) 

Remedies for fever in children


Note that the information in this article is purely informative and should never be used in place of the advice of your treating physicians.

“Symptoms similar to dengue fever.” An outbreak of an unknown disease occurred in Egypt

Rospotrebnadzor has strengthened sanitary and quarantine control over flights arriving from Egypt. In a village 600 km south of Cairo, cases of an unknown disease have been reported, the symptoms of which are similar to dengue fever. Between 200 and 1,000 local residents complained of being unwell. Gazeta.Ru tells what kind of disease this is and how to escape from it.

Rospotrebnadzor has strengthened sanitary and quarantine control over flights arriving from Egypt. About it is reported as on the department’s official website.

According to the Egyptian media and the Ministry of Health, cases of an unknown disease have been recorded in the province of Qena (600 kilometers south of Cairo). The publication “Kommersant” clarifies that from 200 to 1 thousand residents of the village of El-Alikat complained of malaise. About 50 cars with doctors were sent to the settlement, drinking water samples were taken there.

“Symptoms are similar to dengue fever,” Rospotrebnadzor said in a statement. – In connection with the current situation regarding flights arriving from Egypt, Rospotrebnadzor has strengthened sanitary and quarantine control, including with the help of the Perimeter automated information system.

Rospotrebnadzor issued a warning to tourists planning a vacation in Egypt: “In order to prevent infectious and parasitic diseases transmitted by insects, it is necessary to take precautionary measures – wear clothing that covers the skin as much as possible, use insect repellents and insecticides (repellents and insecticides), and screen windows and doors indoors.”

“Upon returning from the host country and in case of deterioration of the condition, you should consult a doctor, be sure to tell him about the place of your trip,” the experts advised.

Rospotrebnadzor cooperates with the Egyptian side and international organizations to obtain information about the nature of the disease, the risks of its cross-border spread, and the preventive and anti-epidemic measures being taken.

“The situation is under the control of the Service,” the department said in a statement, which clarified that so far there were no cases of infection with an unknown disease recorded in Egypt in Russia.

“There is no unknown Egyptian disease in Russia, but dengue fever, the symptoms of which are noted in patients in Egypt, occurs periodically. So, last year in our country 29cases. All are among citizens who arrived from southern countries, ”the message says.

Dengue (“bone-break fever”) is a viral infection that is transmitted to humans from mosquitoes (it is not transmitted by airborne droplets from person to person). The incidence of dengue is growing: if in 2000 there were 505,430 cases of infection with this infection, then in 2019 – 5.2 million ( data of the World Health Organization, WHO).

Symptoms of the disease: high fever, severe headache, pain behind the eyeball, muscle and joint pain, nausea, vomiting, swollen glands, rash.

“Most dengue patients are asymptomatic or have mild symptoms and improve within one to two weeks. In rare cases, dengue can be severe and lead to death,”

says on the WHO website.

Dengue is more common in areas with tropical and subtropical climates. These are Southeast Asia (Thailand, Indonesia, China, Malaysia, Japan, Vietnam, Myanmar, Singapore, Philippines), India, Africa (Mozambique, Sudan, Egypt), tropical and subtropical zone of North, Central and South America (Mexico, Honduras, Costa Rica, Puerto Rico, Panama, Brazil, etc.).

“Most cases of dengue fever can be treated with pain medication at home. There is no specific treatment for dengue, WHO experts write. — The focus is on the treatment of pain symptoms. Acetaminophen (paracetamol) is often used to relieve pain. Non-steroidal anti-inflammatory drugs such as ibuprofen and aspirin should be avoided as they may increase the risk of bleeding. There is a vaccine against the disease called Dengvaxia, which is indicated for people who have had dengue at least once and live in areas where it often occurs.

In 2019, a record number of cases of dengue were reported worldwide. All regions were affected. Only in the countries of America then 3.1 million cases were registered, of which more than 25 thousand cases were classified as severe. A significant number of cases of dengue have been reported in Asian countries: Bangladesh (101,000), Malaysia (131,000), Philippines (420,000) and Viet Nam (320,000).

Imported cases of fever are registered annually in Russia. Most often, the disease is brought by tourists.

Hemorrhagic fever disrupted children’s recreation

Check-in of the first shift at children’s health camps located on the territory of the Saratov nature park “Kumysnaya Polyana” and in the Tatishchevsky district of the Saratov region was disrupted due to an outbreak of hemorrhagic fever with renal syndrome (HFRS). This severe infectious disease, which is carried by rodents, can lead to acute kidney failure. To date, there are 333 infected people in hospitals in the region, one person has died. In camps where shifts could not start on time, deratization is being carried out. In the public chamber of the region, the cancellation of arrivals of children is supported.

Photo: Dmitry Lebedev, Kommersant / buy photo

In the Saratov region, the arrival of the first shift to children’s camps located in the forest area of ​​the Kumysnaya Polyana natural park (Saratov) and in the neighboring Tatishchevsky district was canceled. This is associated with an outbreak of hemorrhagic fever with renal syndrome (HFRS). The first shift was supposed to start in the first half of June, but the control of the quality of deratting showed unsatisfactory results, experts announced the high activity of the natural focus of HFRS, and the races were canceled due to “high epidemiological risks,” the department of Rospotrebnadzor for the Saratov region specified. In total, there are 14 children’s health institutions in the Saratov forest. Information about the new arrival dates for children was promised to be posted on the website of the city education committee. The Ministry of Social Development of the region noted that the families of children who planned to rest in the camps of Saratov and the Tatishevsky district will be offered rest in other recreational institutions and municipal day camps.

HFRS (also known as “mouse fever”) is a viral infection transmitted by rodents. Infection occurs mainly by airborne dust: a person inhales contaminated dust. There is also evidence that mouse fever is transmitted to humans by the alimentary route, when water or food is infected with the secretions of infected rodents, or fever passes to humans with an infection that enters the body with dirty hands. HFRS is characterized by damage to small vessels, hemorrhagic diathesis, hemodynamic disorders, kidney damage with the development of acute renal failure. On the territory of the Saratov region there are several foci of this disease.

The authorities report a decrease in the incidence of the disease during the past week. According to the regional Ministry of Health, as of June 3, 333 infected people remain in the medical institutions of the region. Over the past few days, five people have been admitted for treatment, 234 patients have been discharged.

“In general, the diagnosis of HFRS was confirmed in 348 residents of the region, 54 were removed,” said the head of the regional Ministry of Health, Natalia Mazina. According to official data, one death from HFRS was registered: on May 30, a young woman with symptoms of the disease was admitted to one of the Saratov hospitals in critical condition, who died less than a day later, despite the medical assistance provided. Currently, the investigative department for the Oktyabrsky district is checking this fact.

The local Rospotrebnadzor said that specialists had issued more than 300 orders to heads of management companies, chairmen of non-profit gardening cooperatives, owners of markets and shopping malls in Saratov to take preventive measures.

The Ministry of Natural Resources and Ecology of the region organized a duty of specialists to limit the visits to the forest area by the population. As of June 1, deratization was carried out in Saratov on an area of ​​over 1.9thousand hectares, liquidated 102 unauthorized dumps, carried out sanitary felling of trees and shrubs on an area of ​​27 hectares, as well as clearing dead wood and overgrowth on an area of ​​127 hectares. Specialists of the Russian Research Anti-Plague Institute “Microbe” (in the system of Rospotrebnadzor) monitor the effectiveness of derat control at Kumysnaya Polyana. Governor Valery Radaev instructed to take areas with a high incidence of HFRS “under special control” and take “all necessary measures to eliminate the risks of further spread of the disease.”

The children’s recreational and educational center “Dubki” in the forest area refused to comment on the situation, saying that “questions should be asked to Rospotrebnadzor.”

The camp noted that there is no focus of this disease on its territory, deratization and control of its quality were carried out.

Elena Sokolenko, executive director of the Beryozka children’s sports and recreation center on the territory of Kumysnaya Polyana, also reported that the facility had been deratized, and an examination by the Rospotrebnadzor showed that there was no outbreak of HFRS on the territory. “Two weeks ago, we had a meeting of young policemen – 850 children from all over the region came, plus 100 adults. Of these, 300 people lived in the center for three days. There was no information that someone, God forbid, fell ill,” said Ms. Sokolenko. According to her, the cancellation of the check-in did not affect the activities of the center – the shift, in accordance with the schedule, should open on June 14, before that the deratization of the territory will be carried out again.

Nikolai Popov, a representative of the Microbe Institute, noted that an outbreak of HFRS occurs once every five to seven years, but this year it is on a larger scale, since the increase in the number of carriers of the disease began last fall: “The winter was warm.