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Identifying a fever is relatively simple if a person has a thermometer. Even without one, there are certain ways of telling whether or not a person has a fever. It is especially important to monitor fevers in babies and children.
Most fevers need no treatment, but some home remedies can ease the symptoms. That said, anyone with a very high fever should see a doctor for a full diagnosis.
A person should seek professional medical help if they have a fever alongside:
- other severe or worsening symptoms
- difficulty breathing and chest pain, especially if they have symptoms of COVID-19
- severe pain or swelling
It is also important to see a doctor if these symptoms occur after recent surgery.
In this article, learn more about how to tell if a person has a fever.
Many people can recognize when they feel feverish. Some describe it as a feeling of warmth.
There is no completely accurate way to diagnose a fever without using a thermometer. However, certain techniques can give a person a good idea of whether or not they have a fever.
These methods include:
Touching the forehead
Touching a person’s forehead with the back of the hand is a common method of telling whether or not they have a fever. If the person has a fever, their forehead may feel very hot.
This can be inaccurate, but it may provide some general information.
However, a person with a suspected fever who touches their own forehead may not feel anything unusual. For this reason, it is important to ask someone else for help.
A person may also be able to check for a fever by resting their cheek against the person’s forehead. However, this may not be advisable if they suspect COVID-19. A person should always wash their cheek after resting it against someone else’s forehead.
Pinching the hand
Dehydration can be one sign of a fever. To check for dehydration, a person can gently pinch the skin on the back of their hand, then let the skin go and watch it carefully.
If they are well hydrated, their skin will fall back into place very quickly. If the skin moves slowly, the person may be dehydrated.
However, this method can also be inaccurate, as dehydration does not always indicate a fever.
Looking for flushing in the cheeks
Checking in a mirror for any signs of flushed cheeks can help a person tell whether or not they have a fever.
If they do, the cheeks may be reddish or purple, or they may simply have more color than usual.
Checking urine color
Urine color may also help indicate whether or not someone has a fever.
Fevers dehydrate the body, which can prevent it from making as much urine as usual. This leads to more concentrated urine, which may be dark yellow or orange and possibly have an odor.
Looking for other symptoms
Some other signs and symptoms of a fever can include:
- a headache
- soreness and aching
- weak muscles
- sore eyes
- general fatigue
- a loss of appetite
- difficulty concentrating
- swollen lymph nodes
Checking for a fever is straightforward when a person has a thermometer.
There are a few different types of thermometer available. The following sections will describe these in more detail.
Oral thermometers take the temperature in the mouth. Most modern oral thermometers are digital. They usually beep when they complete a reading, which makes them very easy for most people to use.
Oral thermometers are easier to use in adults, as they require a person to close their mouth and keep the thermometer in place for about 20 seconds to get an accurate reading.
The thermometer should rest under the tongue and as close to the center of the mouth as possible. Once it has taken the reading, it will display the person’s temperature.
Ear thermometers measure the temperature of the eardrum. They are more common in doctors’ offices, but at-home versions are also available.
Ear thermometers can give results within a few seconds. This makes them a good option when dealing with very young children, who may find it difficult to sit still for a prolonged period of time.
However, ear thermometers can give less accurate readings than other types.
To use an ear thermometer, hold the device up to the ear, with the sensor pointing inward, down the ear canal toward the eardrum. Turn on the thermometer, and wait for it to signal that the reading is complete.
Forehead thermometers are becoming more popular for home use. They tend to be accurate, but not as accurate as rectal thermometers.
Forehead thermometers are a good option for use in children, as they do not require them to sit still for a long time.
There are two different versions available. One type, when a person places it on the temporal artery in the forehead, uses infrared light to measure a person’s temperature.
The second type is a plastic strip thermometer that a person can place on the forehead. These strips can detect a fever, but they do not give an exact reading. They only show if a person’s temperature is high or low.
A rectal thermometer takes the temperature of the rectum. Although it may not be the easiest or most comfortable option, it does provide highly accurate readings.
As some researchers note, rectal thermometers give more accurate readings than ear or oral thermometers.
To use a rectal thermometer, apply a lubricant to the tip and gently insert it about half an inch (1.3 centimeters) into the rectum. A person can do this with an oral thermometer, or they can purchase one designed for rectal use.
Rectal thermometers may be the best option when caring for infants. Getting an accurate reading is vital when a baby may have a fever or need medical attention.
A range of thermometers is available for purchase online.
It is important to catch fevers in infants and children early, before their temperatures become very high.
Beyond feeling very hot, an infant or young child with a fever may:
- have skin that is red or flushed
- be irritable
- be unusually tired
- have difficulty drinking or breastfeeding
A fever in a child is any temperature over 101.3°F (38.5°C). Older children may show many of the same symptoms as adults.
Most fevers result from infections, which trigger the body’s natural defenses. The body’s temperature rises, attempting to kill off harmful bacteria or viruses.
Types of infection that can cause a fever include:
- upper respiratory tract infections, such as a cold or flu
- lower respiratory tract infections
- skin infections
- urinary tract infections
- gastrointestinal infections
Other health issues that can lead to a fever include:
- physical exertion
- reactions to certain medications
- chronic conditions, such as rheumatoid arthritis
- cancerous growths
The treatment options for a fever usually involve addressing the underlying cause and controlling any symptoms.
The following sections will discuss some of these options in more detail.
Over-the-counter medications are often the first-line treatment for a fever.
Nonsteroidal anti-inflammatory drugs can usually help reduce a fever and its accompanying symptoms, such as pain. However, if a person suspects COVID-19, they should not use anti-inflammatory drugs, as these can lower a person’s immune response.
Common examples of these drugs include:
Never give aspirin to a child, as there is a risk of a life threatening complication called Reye’s syndrome.
Fluid intake is crucial when a person has a fever, as the process of raising the body’s temperature uses a lot of water.
Drinking plenty of water throughout the day helps combat the effects of the fever and prevent dehydration.
It may also be helpful to drink soup broth. The salts it contains can help replenish the body’s electrolytes when a person is sweating.
If a fever results from exertion or heatstroke, medications may not help. Instead, a person needs to cool down.
Sitting in a cool room may help, but avoid extreme temperatures. Do not cool off by taking a very cold bath or shower, for example. A cold bath or shower can cause a person to shiver, raising their body temperature even higher.
However, sponging the body with lukewarm or cool water may help, as the water will evaporate and cool the skin.
A fever often requires no medical treatment. It will usually go down on its own in time. People can, however, focus on relieving their other symptoms.
However, adults with very high fevers — above 103°F (40°C) — should seek medical help.
Children may need to see a doctor sooner than this. Infants younger than 3 months old should receive medical attention if they have a rectal fever of over 100.4° F (38°C).
Also, anyone who has had a fever for more than 48 hours should see a doctor for a diagnosis and treatment.
Some early symptoms of COVID-19 may include:
- a fever
- a dry cough
- a low appetite
- shortness of breath
If a person has any of these symptoms, the Centers for Disease Control and Prevention (CDC) recommend that they stay at home and, as much as possible, stay away from other people.
They should also wear a cloth face covering if other people are near.
If they also start to experience the following symptoms, they or someone nearby should call the emergency services and let the operator know that they may have COVID-19:
- difficulty breathing
- severe chest pain
- a bluish tinge to the skin, due to a lack of oxygen
- confusion or changes in consciousness
A fever is the body’s reaction to various issues, including infection, sunburn, and dehydration.
A thermometer is the most accurate tool for diagnosing a fever, but other techniques can also help a person tell.
A fever usually resolves on its own. However, a person should see a doctor if a fever is very high or does not go down after 48 hours.