Fever in adults – Harvard Health

Fever is one of the body’s most effective ways of fighting infection. It is part of your body’s defense against infection-causing germs.

You get a fever most often when your body is trying to kill infectious invaders such as viruses or bacteria. A higher body temperature helps the immune system respond more vigorously to the attack, and makes it harder for these microbes to survive.

What is considered a fever in adults?

The average body temperature is 98.6° F (37°C). But “normal” body temperature varies from person to person. It also changes during the day, rising a bit after you eat or exercise. Body temperature is often higher in the afternoon than it is when you wake up in the morning.

Fever means a body temperature of 100.4° F (38°C) or higher.

High fever in adults

While any temperature above your normal temperature range is considered a fever, there are different levels of fever severity:

• Low-grade: 99. 1 to 100.4 F (37.3 to 38.0 C)
• Moderate-grade: 100.6 to 102.2 F (38.1 to 39.0 C)
• High-grade: 102.4 to 105.8 F (39.1 to 41 C)

When to worry about fever

If you have a fever over 104°F (40°C), you should call your doctor.

Seek medical help right away if you have a fever along with any of these symptoms:

• seizure
• loss of consciousness
• confusion
• stiff neck
• trouble breathing
• severe pain anywhere in the body
• swelling or inflammation of any part of the body
• vaginal discharge that is discolored or smells bad
• pain when urinating or urine that smells bad.

Causes of fever

An infection, such as the flu, is the most common cause of fever.

Other conditions can also cause a fever. These include diseases that produce inflammation, such as rheumatoid arthritis; reactions to drugs or vaccines; and even certain types of cancers.

Accompanying symptoms

The following symptoms may also accompany fever:

• sweats
• chills
• headache
• achy muscles
• lack of desire to eat
• rash
• restlessness
• weakness.

A very high fever can cause confusion, extreme sleepiness, irritability, and seizures.

Diagnosing the cause of a fever

To help determine why you have a fever, your doctor will ask you about:

• other symptoms such as coughing, abdominal pain, vomiting, diarrhea, or pain when urinating
• recent surgeries or injuries
• recent vaccinations
• new drugs you may be taking
• recent travel, particularly travel abroad.

How to treat a fever at home

By itself, fever is usually harmless, though a high fever can be miserable. These steps may help you feel better:

• Drink plenty of fluids to help cool your body and prevent dehydration.
• Eat light foods that are easy to digest.
• Get plenty of rest.
• Take ibuprofen (Advil, Motrin, or others), naproxen (Aleve, Naprosyn, or others), or acetaminophen (Tylenol, others) to help relieve head and body aches and lower your temperature.
• Take a slightly warm (not cool) bath, or apply damp washcloths to the forehead and wrists.

Image: yacobchuck/Getty Images

Home Treatment and When to See a Doctor

Nationwide Children’s Hospital

Fever is an increase in the body’s temperature above normal. Body temperature is usually lowest in the morning and goes up through the day. Each person’s body temperature can be different. It is hard to give an exact temperature for a fever, but most health care providers agree that a fever is a temperature of 100. 4˚ Fahrenheit (F) or 38˚ Celsius (C) or higher.

Fevers can show that the body is fighting an infection from a virus or bacteria. It can also happen after getting a vaccine, from getting overheated, or from a very bad sunburn. Many times, the fever does not need to be treated and will go away on its own.

How to Take a Temperature

The type of thermometer used may make a difference.

• To take a temperature, use a digital thermometer. Never use a mercury thermometer.
• Rectal (in baby’s bottom) thermometers are the most accurate.
• Forehead (temporal artery) thermometers are the next best choice if used the right way.
• Oral (mouth) and ear (tympanic) thermometers can be used if done properly. For oral temperatures, wait 30 minutes after drinking something hot or cold. For ear, wait 15 minutes after coming in from the cold.
• Lastly, an axillary (armpit) temperature can be used as a quick check but it is not very accurate.

The best ways to check your child’s temperature depends on their age.

• Under 3 months:  rectal or forehead thermometers
• 4 months or older:  rectal, forehead, or axillary thermometers
• Older than 6 months:  rectal, forehead, ear, or axillary thermometers

• 4 years old or older:  oral (mouth), forehead, ear, or axillary thermometers

Be sure to tell your child’s health care provider which method you used.

Home Treatment

A fever may not need to be treated unless your child is uncomfortable. Even higher temperatures are not usually dangerous unless they have a long-term illness.

• Dress your child in light clothing. Over dressing them can trap the body’s heat and make the temperature go higher.
  • Babies under age 1:  Dress them in a sleep sack or wearable blanket. Do not put loose blankets over them.
  • Children over age 1:  While sleeping, cover them with a sheet or light blanket.
• Give extra fluids.
  • Babies under age 1:  Continue to give breast milk and formula. They should not be given water. If they are older than 6 months, you can give Pedialyte®.
  • Children over age 1:  Offer extra liquids to drink, like water, diluted 100% juice, popsicles, or Pedialyte.
• Your child may not want to eat much. Offer soft foods often and in small amounts but do not force them to eat.
• Give sponge baths or let your child soak in a tub. Water should be lukewarm, not too hot or cold. Use a wash cloth to sponge the water over your child’s body (Picture 1).
  • Do NOT add alcohol to the water. It can be dangerous.
  • Recheck your child’s temperature 15 minutes after the bath. If the temperature is 103˚F (39.4˚C) or is going higher, repeat the sponge bath.
• Over-the-counter medicines can help lower a fever. Read the label on the bottle to know the right dose for your child.
  • Acetaminophen (Tylenol^®) may be used in all children over 2 months.
  • Ibuprofen (Advil^®, Motrin^®) may be used in children over 6 months.
  • Do NOT give aspirin to children (Picture 2). Aspirin has been linked to a disease called Reye’s syndrome, which can be fatal. 

When to Call the Health Care Provider

Call your child’s health care provider right away if your child:

• Is younger than 3 months of age and has a temperature of 100.4˚F (38˚C) or higher.
• Is older than 3 months and has a temperature:
  • Of 104 ˚F (40 ˚C) or above.
  • Above 102˚F (38.9˚C) for more than 2 days or keeps coming back.
  • That has been treated to bring it down, but it has not worked.
• At any age, has a fever and:
  • Looks very ill, is very fussy, or very drowsy.
  • Is not eating or drinking and shows signs of dehydration – dry or sticky mouth, sunken eyes, dark urine, dry diapers, or not urinating.
  • Has a stiff neck, bad headache, very sore throat, painful stomach ache, vomiting, or diarrhea.
  • Has an unusual rash
  • Has been in a very hot place, such as an overheated car.
  • Has immune system problems that make them more likely to get sick, such as sickle cell disease or cancer, or takes a medicine that weakens the immune system.

Call 911 or go to the emergency department if your child has trouble breathing, has a seizure, or is hard to wake up.

Fever (PDF), Arabic (PDF), Nepali (PDF), Somali (PDF), Spanish (PDF)

HH-I-105 10/75 Revised 2/22 Copyright 1975, Nationwide Children’s Hospital

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Quick answer: 104 7 Is a high temperature for a dog?

Pyrexia in dogs. Fever, medically called hyperthermia, can be defined as an increase in body temperature in dogs that is above normal. With a normal range of 99.5 to 102.5 Fahrenheit, a body temperature of at least 103.5°F (39.7°C) can be considered a fever.

A dog is said to have a fever when its temperature reaches 103 degrees or more. If so, it’s time to head to the vet. Temperatures of 106 degrees and above can damage your pet’s internal organs and lead to death, so never wait until it gets to this point.

If your dog has a temperature above 103 F, you should call your veterinarian. A fever above 106 F is an emergency that must be treated immediately. If your dog’s temperature is above 105 F, you can lower his body temperature by soaking his coat with cool water, especially around the ears and legs.

A normal temperature of 100° to 104° F (37.8° to 40° C) is beneficial for sick children. MYTH. Fever above 104°F (40°C) is dangerous. They can cause brain damage.

Severe fever ranges from 103 to 104 F. Dangerous temperatures are high fevers that range from 104 to 107 F or higher (very high fever is also called hyperpyrexia).

When describing fever in dogs, temperature is usually defined as above 103.5–104°F (39.7–40°C), with no indication of the duration of the fever.

Tylenol® is an opioid-free pain reliever sometimes given to dogs for pain and fever.

Temperatures below 103 can usually be controlled at home within 24 hours. But if the temperature rises or lasts longer than a day, you should contact your veterinarian. Temperatures of 106 degrees and above can cause damage to the dog’s internal organs and lead to death.

Signs of lethargy include anorexia, shortness of breath and a sudden change in behavior. One of the simple causes of lethargy in dogs is warm weather. This causes the so-called “expiring lethargy”. When the temperature cools down or the dog cools down, his lethargy should subside.

Call your pediatrician if your child’s rectal temperature falls below 97. 7. Your child has a fever for more than five days. Your pediatrician may need to further investigate underlying causes. Your child’s temperature is above 104 F (> 40 C).

As soon as the temperature goes beyond the high level, the temperature rises to a dangerous level (104-107 F) in an adult. When the temperature reaches a dangerous level, also known as hyperpyrexia, a medical emergency arises and you should seek immediate medical attention.

Possible acetaminophen (Tylenol) and non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen (Advil, Motrin). If necessary, the doctor will treat any underlying infection. If you have a high fever, stay hydrated by drinking plenty of fluids.

Share on Pinterest Doctors consider a temperature over 104°C (40°F) to be a high fever. In general, adults should seek medical attention if their temperature exceeds 104°F (40°C). Doctors consider this temperature to be a high fever.

Also, when your child’s temperature rises to 104 or 105 degrees Fahrenheit or does not drop sharply while taking paracetamol or ibuprofen, you should contact your child’s pediatrician, who will likely refer him or her to urgent care or an emergency room.

Reducing temperature naturally with plants

Fever, a common and frequent disease that everyone experiences, is a symptom that manifests itself in an abnormally high body temperature in the absence of any intense physical effort. Plants can help in its treatment.

Indeed, the normal average human body temperature is 98.6°F (37°C).
Depending on the person, this average may be closer to 97.7°F (36.5°C) or 99.5°F (37.5°C).

The term “fever” is used whenever the resting body temperature rises to 100.4°F (38°C) or higher.

In both children and adults, fever is usually the body’s immediate response to infection.

As long as the thermometer does not show a body temperature above 105.8°F (41°C), the fever itself is not dangerous. Thus, in most cases, no special treatment is required.

However, if the temperature exceeds 104°F (40°C), this increase in body temperature is considered a “serious and immediate health risk”, especially for young children. In this case, it is imperative to meet with a consultant doctor.

But is it possible to fight fever with plants? Why? When and how? Let’s look around…

• An important note about the coronavirus – if you are experiencing any symptoms (fever, sore throat, cough, muscle aches, fatigue), use the phone and call your doctor. Do not go to the doctor’s office unless asked to do so. The remedies presented here may relieve symptoms, but they are not a substitute for professional medical attention and follow-up.

Fever, basic facts about this symptom

Definition of fever

Derived from the Latin root word “ febris “, fever is defined as an abnormal increase in body temperature without the patient exerting any physical effort. Temperature is measured with a thermometer when the temperature is over 100.4 °F (38 °C).

Thus, it is the physiological reaction of the body when it tries to resist possible changes or disorders that occur in the body.

Fever and medicine, short story

In 1868, the German physician Karl Wunderlich first introduced fever as a symptom and not as a disease as such. He established that the normal human body temperature is between 98.6°F (37°C) and 99.5°F (37.5°C).

Approximately 150 years later, modern medicine expanded part of his teaching, as it was observed and explained that body temperature is unique to each person. It would be a mistake to arbitrarily assume that it is within 98.6-99.5°F (37-37.5°C) for all.

2016 showed progress in resolving this breakthrough thanks to scientists working at the Boston Children’s Hospital in Massachusetts (USA). Using Apple’s “Feverprints” app, they conducted a study based on information collected by patients with fever.

Causes and forms of fever

An abnormal increase in body temperature is usually a reaction to an infection.

Indeed, after an infection, such as a urinary tract infection or mild otitis media, the body reacts and raises core body temperature. This has the effect of increasing the exposure and effectiveness of leukocytes.

Fever is often associated with pain, muscle aches and shaking or trembling, but there are a number of other symptoms, namely:

– broncho-pulmonary diseases

– gastroenteritis sinusitis, pharyngitis, laryngitis).

In fact, if these symptoms and disorders are accompanied by neck stiffness, hypotension, confusion or delirium, difficulty breathing, etc., it is very important to consult a doctor, especially if the fever continues for at least 72 hours.

In other cases, fever is the first observable sign of a potentially serious infectious disease.

The following may be noted as relevant:

– kidney infection or pyelonephritis

– encephalitis

– meningitis

– foreign bodies (grafts, allergens)

– changes in tissues or organs of the body (for example, in the event of a heart attack)

– sepsis

– reaction to certain medications

– the presence of cancer cells

– certain diseases (including lupus)

– and deep abscesses.

Although many cases of fever remain unresolved to this day, some systemic, neoplastic or hematological diseases may be additional possible triggers.

How to Reduce Fever Naturally

Like any other symptom or disease, every confirmed case of fever should not be ignored.

Although this rarely requires urgent treatment (depending on the patient’s age and medical history), it is important to take steps to reduce the temperature.

The first steps are to ask the patient to take off their clothes, lower the temperature in the patient’s room, remove the cover, and drink more water from the patient.

There are a number of medicines specifically designed to help reduce fever.

What about natural herbal solutions?

Here are a few key things to know:

– often used as an herbal tea for children, linden tree or linden – an antipyretic medicinal plant.

To make a cup of linden or linden herbal tea, measure out one teaspoon of dried flowers for about 7 fl. $12.99 oz (200 ml) water.

– As a tablet or gelatin capsule, white willow is a very effective antipyretic. It is extremely important to consult a specialist about the correct dosage to be used in case of fever.

• Elderflower is recommended to be taken as a softgel or as an herbal tea to help detoxify when you have a fever. To prepare a course, an adequate dosage must be determined by an expert on an individual basis.
• Finally, decoctions made from calendula are another of the traditional options that are often recommended to reduce fever.

Good to know about fever

If you have a fever caused by an infectious disease (flu), remember:

– Avoid heavy meals

– Rest and stay out of the cold to minimize effort

– Stay hydrated by drinking frequent fluids (broth, sweetened drinks, water or herbal tea).

Some diseases (Still’s disease, hyperthyroidism, Kawaschi’s disease, lymphoma, Crohn’s disease, leukemia, sarcoidosis) can cause episodes of occasional fever.