What Is a Fever?
A fever is a body temperature that is higher than normal. Your body’s temperature is regulated by an area in the brain called the hypothalamus, which acts like an internal thermostat. When the body detects certain conditions—such as an infection, inflammation, or illness—the hypothalamus can raise the temperature to help the immune system work more effectively.
Normal body temperature usually ranges between 97°F and 99°F (36.1°C to 37.2°C), but this can vary from person to person and throughout the day. A temperature of 100.4°F (38°C) or higher is generally considered a fever in adults. In children, a fever is also measured when temperatures exceed 100.4°F rectally, 99.5°F orally, or 99°F under the arm. In infants younger than 3 months, any fever should be evaluated by a healthcare provider.
A fever itself is not a disease. It is a symptom indicating that the body is responding to something, such as a viral or bacterial infection. Common infections like the flu, colds, or stomach bugs can cause fever. Other causes may include reactions to medications, immunizations, heat exhaustion, or inflammatory conditions.
Fevers are typically a normal and healthy immune response. They often go away on their own or with simple home care. However, depending on the person’s age, temperature level, and accompanying symptoms, a fever can sometimes require medical attention.
Normal Body Temperature & When Fever Starts
Normal body temperature can vary from person to person and changes throughout the day. It is typically lower in the morning and slightly higher in the evening. The average normal body temperature is around 98.6°F (37°C), but anything in the range of 97°F to 99°F (36.1°C to 37.2°C) is generally considered normal for most people.
A fever is usually defined as a body temperature of 100.4°F (38°C) or higher. The temperature reading can differ based on the type of thermometer and where it is used on the body. The most accurate readings, especially for infants, are taken rectally.
Fever Temperature Thresholds by Age and Method
| Age Group | Rectal Temperature | Oral Temperature | Ear / Forehead (Temporal/Tympanic) | Under the Arm (Axillary) |
|---|---|---|---|---|
| Infants (0–3 months) | Any temperature of 100.4°F (38°C) or higher — seek medical care immediately | Not recommended | Not recommended | Not recommended |
| Babies & Toddlers (3 months to 5 years) | 100.4°F (38°C) or higher | 100°F (37.8°C) or higher | 100.4°F (38°C) or higher | 99°F (37.2°C) or higher |
| Children (5 years and older) | 100.4°F (38°C) or higher | 100°F (37.8°C) or higher | 100.4°F (38°C) or higher | 99°F (37.2°C) or higher |
| Adults | 100.4°F (38°C) or higher (if rectal used) | 100.4°F (38°C) or higher is considered fever | 100.4°F (38°C) or higher | 99°F (37.2°C) or higher |
Low-Grade vs. High Fever
- Low-grade fever: 99.5°F to 100.3°F (37.5°C to 37.9°C)
Often signals early immune response or mild infection. - Moderate fever: 100.4°F to 103°F (38°C to 39.4°C)
Usually indicates the body is actively fighting infection. - High fever: Above 103°F (39.4°C)
May require medical attention, especially in children or adults with additional symptoms.
In infants younger than 3 months, any fever requires prompt medical evaluation, because their immune systems are still developing and they may not show other clear signs of illness.
Common Symptoms of Fever
A fever is not only identified by a higher-than-normal temperature. The body often shows other physical and behavioral signs when temperature rises. These symptoms can vary depending on the cause of the fever, how quickly the temperature increases, and the age or health of the person.
Below are the most common symptoms associated with fever, along with how they may appear in daily life:
1. Feeling Warm or Hot to the Touch
When fever is present, the skin may feel warm, especially on the forehead, back, or chest.
The person may say they “feel hot,” even if the room temperature is normal.
2. Flushed or Red Face
The face, cheeks, or ears may look red or flushed. This occurs because blood vessels widen as the body attempts to release excess heat.
3. Chills or Shivering
Even though the body temperature is high, a person may feel cold, shiver, or shake.
This happens when the hypothalamus raises the internal temperature and the body tries to “catch up” to the new set point.
4. Sweating
As the fever begins to stabilize or reduce, the body may produce sweat to cool down.
Sweating often increases when the fever is starting to break.
5. Headache
Fever can cause pressure or aching in the head, especially around the temples or forehead.
This happens due to inflammation and changes in blood flow that occur during illness.
6. Body Aches and Muscle Pain
The person may feel generalized pain, soreness, or heaviness in the arms, legs, or back.
This is common with fevers caused by viral infections like the flu.
7. Fatigue or Weakness
Fever often results in low energy, tiredness, or excessive sleepiness.
The body redirects energy toward fighting illness, which can lead to reduced activity and slower movement.
8. Loss of Appetite
Many people do not feel hungry when they have a fever.
This is a normal response as the digestive system slows down while the immune system becomes more active.
9. Dehydration
Fever can lead to fluid loss through sweating and faster breathing.
Signs may include:
- Dry mouth
- Dark, concentrated urine
- Low urine output
- Feeling thirsty
10. Irritability or Behavioral Changes (More Common in Children)
Infants and children may:
- Cry more than usual
- Have difficulty sleeping
- Seem unusually quiet or withdrawn
- Pull at their ears or dislike being touched
They may not be able to describe how they feel, so behavioral signs are important to watch.
Important Note
It is not only the temperature that matters — how the person looks, behaves, and responds provides clues about the severity of illness.
If a person has a high fever and appears very ill, medical attention may be needed.
Fever Symptoms by Age Group
Fever can appear differently based on age, physical development, and communication ability. Infants, children, adults, and animals may each show unique behavioral or physical signs. Recognizing these differences helps determine when home care is appropriate and when to seek medical attention.
Symptoms of Fever in Adults
Adults can usually describe how they feel, so fever symptoms may be easier to identify. Common symptoms include:
- Feeling unusually warm or flushed
- Chills or shaking
- Headache or pressure in the head
- General body aches or muscle pain
- Fatigue, weakness, or low energy
- Sweating, especially when the fever begins to lower
- Loss of appetite
- Dehydration, which may show as dry mouth or darker urine
Most fevers in adults resolve on their own, especially when caused by mild viral infections. However, fever above 103°F (39.4°C), fever lasting longer than 3 days, or fever accompanied by severe symptoms should be evaluated by a healthcare provider.
Symptoms of Fever in Infants and Children
Infants and young children may not be able to communicate how they feel. Because their immune systems are still developing, fevers require closer attention.
Common signs of fever in babies and children include:
- Warm or hot skin, especially on the forehead or torso
- Red or flushed cheeks
- Irritability, fussiness, or unusual crying
- Decreased interest in feeding or drinking
- Reduced urine output (fewer wet diapers)
- Trouble sleeping or unusual drowsiness
- Pulling at the ears (may suggest ear infection)
When to Seek Pediatric Care
- Any fever in babies under 3 months (call a healthcare provider immediately)
- Fever higher than 102°F (38.9°C) in children lasting more than 24 hours
- Fever accompanied by rash, stiff neck, repeated vomiting, trouble breathing, or seizure
Fevers in children are common, but changes in behavior, alertness, and hydration are key signs to monitor.
Symptoms of Fever in Dogs
Dogs can also develop fever due to infection, inflammation, or illness. Because pets cannot verbally describe symptoms, behavioral and physical signs are important to observe.
Common symptoms of fever in dogs include:
- Warm ears, nose, or paws
- Shivering or trembling
- Low activity, fatigue, or weakness
- Loss of appetite
- Rapid breathing or panting
- Dry or warm nose (though a warm nose alone does not confirm fever)
- Red or glassy-looking eyes
- Curling up or seeking warmth when feeling chills
If a dog appears lethargic, refuses food, or has a temperature above 103°F (39.4°C) (measured rectally with a pet-safe digital thermometer), call a veterinarian.
Seek immediate veterinary care if the fever is accompanied by:
- Vomiting or diarrhea
- Seizures
- Difficulty breathing
- Swollen joints or visible pain
- A rash or unexplained swelling (possible tick-related illness)
Fever in dogs may be linked to infections, immune-related conditions, or tick-borne diseases such as Rocky Mountain spotted fever or tick fever, which require prompt veterinary treatment.
What Causes Fever?
A fever is the body’s natural response to something that disrupts its normal balance. The hypothalamus raises the internal temperature when it detects infection, inflammation, or other stress signals. This increase in temperature can help the immune system work more effectively by slowing the growth of certain bacteria and viruses.
Fevers can be caused by infections, reactions to medications or vaccines, heat-related conditions, or inflammatory and autoimmune disorders. In infants, mild fever can also occur during teething, but temperatures typically do not exceed 101°F (38.3°C) in teething-related cases.
Common Causes of Fever and How They Lead to Increased Body Temperature
| Cause | Examples / Conditions | How It Triggers Fever |
|---|---|---|
| Viral infections | Flu, common cold, COVID-19, RSV, viral gastroenteritis | The immune system detects virus particles and releases chemicals (like cytokines) that signal the hypothalamus to raise body temperature. |
| Bacterial infections | Ear infections, strep throat, pneumonia, urinary tract infections, sinus infections | Bacteria release toxins or trigger inflammation, causing the body to raise temperature to help fight infection. |
| Heat exhaustion or overheating | Prolonged sun exposure, intense exercise, dehydration | The body loses its ability to cool itself efficiently, leading to elevated internal temperature. |
| Inflammatory and autoimmune conditions | Rheumatoid arthritis, lupus, inflammatory bowel disease (IBD) | These conditions cause ongoing inflammation that can reset the body’s temperature regulation. |
| Reactions to medications | Certain antibiotics, seizure medications, and blood pressure drugs | Some medications can interfere with the hypothalamus or cause immune reactions leading to fever. |
| Vaccines or immunizations | Routine childhood vaccines, flu vaccine, COVID-19 vaccines | The immune system responds to the vaccine to build protection, which may produce a temporary low-grade fever. |
| Hormonal and metabolic disorders | Hyperthyroidism and other gland-related disorders | Increased metabolic activity or hormone imbalance can raise body temperature. |
| Blood clots or serious systemic illness | Deep vein thrombosis (DVT), infections spreading in the blood | The body increases temperature during severe inflammatory or immune stress. |
| Teething in infants | Occurs around 4–12 months of age | May cause a mild, temporary temperature elevation — usually not higher than 101°F and not a sign of infection by itself. |
Important Note
A fever itself does not determine what condition is present.
Diagnosis depends on other symptoms, medical history, and sometimes laboratory tests.
Special Fever Patterns
Fever does not always appear in the same way. The timing, intensity, and associated symptoms can vary based on the underlying cause. Understanding these different fever patterns can help identify whether the fever is part of a common illness or whether medical evaluation is needed.
Fever During Pregnancy
A fever during pregnancy is not considered a normal pregnancy symptom. However, pregnant individuals can still develop fevers from viral or bacterial infections like the flu, respiratory infections, urinary tract infections, or stomach viruses.
Common symptoms may include:
- Elevated body temperature (100.4°F / 38°C or higher)
- Chills, sweating, or body aches
- Fatigue or weakness
- Headache or sensitivity to light
Why it matters:
During pregnancy, the immune system changes to support fetal development. Certain infections can progress more quickly or cause dehydration, making it important to monitor fever closely.
Real-life example:
A pregnant person with a mild fever may feel unusually tired, sweaty, and weak after simple activities, like walking across a room or climbing stairs.
If fever in pregnancy reaches 102°F (38.9°C) or higher, or lasts longer than 24 hours, contact a healthcare provider.
Fever with No Other Symptoms
Sometimes, a fever may be the only noticeable sign of illness. This can occur when the body is in the early stages of immune response, while the infection has not yet caused respiratory, digestive, or skin symptoms.
Possible scenarios include:
- Beginning phase of a viral infection
- Post-vaccination immune activation
- Mild urinary or sinus infection not yet causing discomfort
Real-life example:
A person may feel warm, tired, and less hungry but have no cough, sore throat, or stomach symptoms.
If a fever persists longer than 3 days with no additional symptoms, medical evaluation is recommended.
Fever at Night
Body temperature naturally rises in the evening. For some illnesses, symptoms may feel worse at night because the body’s temperature regulation shifts and inflammatory chemicals increase during sleep cycles.
This can occur with:
- Viral respiratory infections
- Early stages of flu or COVID-19
- Immune-related conditions
Nighttime fever signs may include:
- Waking up sweating
- Feeling chilled when getting into bed
- Needing extra blankets, then removing them after sweating
Real-life example:
A child may seem comfortable during the day, but at night wakes up sweating and feeling hot, only to become cold shortly after.
Symptoms of Fever Breaking (Recovery Phase)
When the body no longer needs a higher temperature, the hypothalamus gradually returns the temperature set-point to normal. As the fever breaks, the body actively cools itself.
Common signs a fever is breaking:
- Increased sweating
- Skin feels damp or moist
- Feeling suddenly tired or weak
- Temperature slowly returns to normal
Real-life example:
A person who was shivering earlier may now wake up drenched in sweat, with the fever number dropping on the thermometer.
This phase can leave the person feeling exhausted, as the body has used a significant amount of energy to fight illness.
Fever Related to Specific Illnesses
Many medical conditions can include fever as a primary symptom, but the pattern of symptoms that appear along with the fever can help suggest what illness may be present. The conditions below are commonly searched and often associated with fever. Each has distinguishing signs that help differentiate one illness from another.
Symptoms of Dengue Fever
Dengue fever is a viral infection transmitted by mosquitoes. Fever is often high and sudden, sometimes reaching 104°F (40°C). Along with fever, individuals commonly experience severe headaches, particularly behind the eyes, joint and muscle pain, and extreme fatigue. A red or blotchy skin rash may appear several days after the fever begins. Nausea and vomiting are also common. In some cases, symptoms may progress to severe dengue, which requires immediate medical care.
Symptoms of Scarlet Fever
Scarlet fever is caused by the same bacteria that cause strep throat. It typically begins with a sore throat, fever, and swollen glands. A distinctive red rash may develop, often starting on the chest or neck and spreading outward. The skin may feel like sandpaper, and the tongue may appear red and bumpy, sometimes described as a “strawberry tongue.” Headaches, nausea, and stomach pain may also accompany these symptoms. Scarlet fever requires medical treatment to prevent complications.
Symptoms of Valley Fever
Valley fever is an infection caused by inhaling fungal spores found in certain dry geographic regions. It often begins with fever, fatigue, and cough. Some individuals may experience chest pain, shortness of breath, or night sweats. Joint and muscle aches are also common. Symptoms may resemble those of a respiratory virus at first. Most cases are mild, but some infections can progress and require long-term medical care, especially in individuals with weakened immune systems.
Symptoms of Typhoid Fever
Typhoid fever is a bacterial infection that causes a gradual and persistent fever, often rising each day over the course of a week. Common symptoms include abdominal pain, loss of appetite, headache, and severe fatigue. Some individuals may develop constipation or diarrhea. A faint, rose-colored rash may appear on the abdomen or chest in some cases. Typhoid fever requires medical diagnosis and antibiotic treatment.
Symptoms of Yellow Fever
Yellow fever is a viral disease spread by mosquitoes. It often begins with sudden fever, headache, muscle pain, and chills. Nausea and vomiting can occur. After initial improvement, some individuals may enter a toxic phase where fever returns and jaundice (yellowing of the skin and eyes) develops. Dark-colored urine and abdominal pain may also appear. Severe yellow fever requires urgent medical care.
Symptoms of Cat Scratch Fever
Cat scratch fever is caused by bacteria transmitted from cats, usually through a scratch or bite. Fever may develop several days to weeks after exposure. A swollen lymph node near the site of the scratch is common and may be tender or painful. Fatigue, headache, and loss of appetite can occur. In most individuals, symptoms are mild, but persistent swelling or high fever may require medical evaluation.
Symptoms of Rocky Mountain Spotted Fever
Rocky Mountain spotted fever is a tick-borne bacterial infection. Fever typically begins suddenly, along with severe headache, fatigue, muscle aches, and nausea. A rash often appears 2 to 4 days after fever begins, usually starting on the wrists or ankles and spreading to the trunk. Some rashes appear as small red spots or bruises. Early treatment is important to prevent complications.
Symptoms of Hay Fever (Allergic Rhinitis)
Despite the name, hay fever does not cause fever. It is an allergic reaction to pollen or airborne allergens. Symptoms include sneezing, runny or stuffy nose, itchy eyes, throat irritation, and watery eyes. The term “fever” refers to the feeling of warmth or sinus pressure, not an actual rise in body temperature. Hay fever is treated differently than infections and does not respond to fever-reducing medications.
When to See a Doctor
Fever is often a natural part of the immune response and can usually be managed at home. However, there are situations where fever may indicate a more serious condition. The age of the person, the duration of the fever, and any accompanying symptoms are important when deciding whether to seek medical care.
When to Seek Medical Care for Fever
| Age Group | Seek Medical Care If: | Urgent / Emergency Symptoms (Seek Immediate Care or ER): |
|---|---|---|
| Infants (0–3 months) | Any fever 100.4°F (38°C) or higher | Difficulty waking, refusal to feed, persistent crying, trouble breathing |
| Infants & Children (3 months to 5 years) | Fever above 102°F (38.9°C) lasting more than 24–48 hours | Seizure, stiff neck, rash, severe vomiting, dehydration (few wet diapers), trouble breathing |
| Children (5 years and older) | Fever lasting more than 3 days, or returning after improving | Confusion, severe headache, persistent chest pain, inability to drink fluids |
| Adults | Fever above 103°F (39.4°C) or fever that does not improve with OTC fever-reducing medicines | Chest pain, confusion, stiff neck, difficulty breathing, seizure, rash spreading quickly |
| Pregnant Individuals | Fever 102°F (38.9°C) or higher, or fever lasting more than 24 hours | Persistent abdominal pain, dizziness, reduced fetal movement, dehydration |
| Older Adults or Immunocompromised Individuals | Any fever of 100.4°F (38°C) or higher, or fever with no obvious cause | Sudden weakness, trouble staying awake, shortness of breath, severe dehydration |
Signs That Require Immediate Emergency Care (Any Age)
Seek immediate emergency medical attention if fever is accompanied by:
- Seizure
- Difficulty breathing or wheezing
- Confusion, disorientation, or inability to stay awake
- A stiff neck
- Severe headache with fever
- Purple or rapidly spreading rash
- Persistent vomiting or inability to keep fluids down
- Fever above 105°F (40.5°C) that does not improve after medication
These signs may indicate serious infection, meningitis, severe dehydration, or other urgent medical conditions.
Key Point
The severity of symptoms and the person’s behavior or alertness are often more important than the number on the thermometer.
How Fever Is Diagnosed
Diagnosing a fever begins with confirming body temperature and assessing other symptoms that may point to the underlying cause. A thermometer is the most reliable way to measure temperature, and the method of measurement can affect accuracy.
Step-by-Step: How Fever Is Checked
- Measure body temperature using a thermometer.
- Note the method used (oral, rectal, ear, forehead, or underarm), as readings vary.
- Look for additional physical symptoms, such as rash, cough, vomiting, sore throat, or pain.
- Review recent activities, including travel, contact with sick individuals, vaccinations, or exposure to extreme heat.
- If symptoms are unclear or fever persists, a healthcare provider may perform tests to identify the cause.
Common Thermometer Types and Their Use
| Thermometer Type | Where It Measures Temperature | Best For | Notes |
|---|---|---|---|
| Digital Oral Thermometer | Under the tongue | Children (5+) and adults | Avoid eating/drinking 15 minutes before measuring. |
| Rectal Digital Thermometer | Inside the rectum | Infants and babies under 3 years | Considered most accurate for infants and young children. |
| Ear (Tympanic) Thermometer | Inside the ear canal | Children and adults (not infants under 6 months) | Can give inaccurate readings if earwax or infection is present. |
| Forehead (Temporal Artery) Thermometer | Across the forehead | Infants, children, and adults | Non-invasive and quick; accuracy can vary by technique. |
| Underarm (Axillary) Digital Thermometer | Under the arm | Initial screening for infants or children | Least accurate; confirm with a more reliable method if fever is suspected. |
Note: Mercury thermometers are no longer recommended due to safety concerns.
When Additional Medical Testing May Be Needed
Testing is not always required for mild, short-lasting fever. However, a healthcare provider may order tests if:
- Fever lasts more than 3 days
- Fever returns after improving
- There are symptoms of a specific infection
- The person has a weakened immune system
- The cause is unclear (fever of unknown origin)
Possible Tests Used to Determine the Cause of Fever
- Blood tests (to check for infection or inflammation)
- Urine test (to detect urinary tract infections)
- Nasal or throat swabs (for flu, strep throat, RSV, or COVID-19 testing)
- Stool sample (if diarrhea is present)
- Chest X-ray (if pneumonia is suspected)
- Culture tests (to identify bacteria in blood, urine, or body fluids)
Healthcare providers determine which tests are necessary based on symptoms, exposure history, and clinical examination.
Treatment & Home Care
Most fevers can be managed safely at home, especially when they are caused by mild viral infections. Treatment focuses on comfort, hydration, and monitoring. The goal is not always to eliminate the fever completely, but to help the person feel better while the body works to fight the underlying cause.
1. Fever-Reducing Medications
Common medications used to lower fever include:
- Acetaminophen (Tylenol)
- Ibuprofen (Advil, Motrin) — for children over 6 months and adults
Important Medication Rules:
- Always follow age-appropriate dosing instructions.
- Do not alternate acetaminophen and ibuprofen unless advised by a healthcare provider.
- Never give aspirin to children or teenagers.
Aspirin is associated with Reye’s syndrome, a rare but serious condition affecting the liver and brain.
2. Hydration and Fluids
Fever increases fluid loss through sweating and faster breathing, which can lead to dehydration.
Recommended fluids:
- Water
- Oral rehydration solutions (especially for children)
- Clear broths or diluted fruit juices
Signs of dehydration to watch for:
- Dry mouth
- Dark or concentrated urine
- Low urine output
- Sunken eyes (especially in children)
Encourage small sips frequently, especially if the person feels nauseated.
3. Rest and Comfort
The body uses energy to fight infection. Extra rest helps recovery.
- Encourage quiet activities or sleep.
- Avoid strenuous physical activity.
- Ensure a cool, comfortable room temperature.
4. Bathing and Cooling Measures
A lukewarm bath can help reduce temperature gradually.
Do:
- Use room-temperature or lukewarm water
- Remove excess layers of clothing
- Apply a light blanket if chills occur
Do Not:
- Use cold baths or ice packs (this can cause shivering and raise internal temperature further)
- Use alcohol rubs (they can be absorbed through the skin and are not safe)
5. Monitoring Temperature
- Re-check temperature every 4 to 6 hours unless otherwise directed.
- Track fever patterns (higher at night is common).
- Observe behavior — this is often as important as the temperature number itself.
Do and Don’t Guidelines for Fever Home Care
| Do | Don’t |
|---|---|
| Offer fluids frequently | Give aspirin to children or teens |
| Use acetaminophen or ibuprofen as directed | Use cold baths or ice packs |
| Keep clothing light and breathable | Over-bundle or layer blankets tightly |
| Let the person rest and sleep more than usual | Force eating if appetite is low |
| Use a digital thermometer correctly | Alternate fever medications without guidance |
| Seek medical care if fever lasts > 3 days or has warning signs | Ignore persistent or worsening symptoms |
Key Reminder
The goal is comfort and monitoring. Fever itself is part of the body’s defense — what matters most is how the person looks, behaves, and stays hydrated.
Summary
A fever is a higher-than-normal body temperature and is most often a sign of the body’s natural response to infection or inflammation. While fever can cause discomfort, it helps support the immune system. The most important considerations are how the person feels, hydration level, and the symptoms that accompany the fever. Mild fevers can usually be managed at home with rest, fluids, and fever-reducing medications when needed.
Seek medical care if the fever is very high, lasts more than a few days, occurs in infants, or is accompanied by warning signs such as difficulty breathing, seizure, stiff neck, confusion, severe dehydration, or rash.
Frequently Asked Questions (FAQs)
1. What are the symptoms of a fever?
Common symptoms include feeling warm, flushed skin, chills, sweating, headache, muscle aches, fatigue, and loss of appetite. Some people may also experience dehydration or irritability.
2. What temperature is considered a fever?
A fever is generally 100.4°F (38°C) or higher when taken orally. Rectal temperature is most accurate for infants and young children.
3. What are the symptoms of fever in infants?
Infants may have warm skin, irritability, poor feeding, or fewer wet diapers. Any fever in infants under 3 months requires medical attention.
4. What are the symptoms of fever in adults?
Adults commonly experience chills, sweating, fatigue, muscle aches, and weakness. High fever or fever lasting more than 3 days should be evaluated by a healthcare provider.
5. What are the symptoms of fever in dogs?
Dogs may show warm ears or nose, lethargy, loss of appetite, shivering, or red eyes. A rectal temperature above 103°F (39.4°C) suggests fever and may require veterinary care.
6. Can fever be the only symptom of illness?
Yes. Early viral or bacterial infections may present with fever before other symptoms develop. If fever lasts longer than 3 days without additional symptoms, seek evaluation.
7. Is fever a symptom of pregnancy?
Fever is not a typical pregnancy symptom. If a pregnant person develops a fever, it may indicate infection and should be monitored closely.
8. Can fever happen only at night?
Yes. Body temperature naturally rises in the evening. Some infections also worsen symptoms during nighttime rest cycles.
9. What does it mean when a fever is breaking?
As the fever lowers, sweating often increases, skin may feel damp, and the person may feel tired or weak. This is part of the recovery process.
10. What are the symptoms of dengue fever?
Dengue fever may cause high fever, severe headache, joint pain, muscle pain, fatigue, nausea, and sometimes a skin rash.
11. What are the symptoms of scarlet fever?
Scarlet fever includes a red rash, fever, sore throat, swollen glands, and a red “strawberry” tongue.
12. Is hay fever actually a fever?
No. Hay fever is an allergic reaction, not an infection. It causes sneezing, itchy eyes, and a runny nose, but does not cause body temperature to rise.
13. When should I see a doctor for fever?
Seek care if fever lasts longer than 3 days, goes above 103°F (39.4°C) in adults, or if severe symptoms such as stiff neck, confusion, rash, seizure, or shortness of breath occur.
14. Can dehydration cause fever?
Yes. Dehydration may lead to elevated body temperature, especially in children. Increasing fluid intake is important during fever.
15. Can fever be a symptom of cancer or autoimmune disease?
In some cases, persistent or unexplained fever may be associated with chronic illness. A healthcare provider may perform tests if fever does not resolve or has no clear cause.
16. Is it okay to use cold water or ice packs to reduce fever?
No. Cold baths and ice can cause shivering, which can raise internal temperature. Use lukewarm water instead.
17. Can I alternate acetaminophen and ibuprofen for fever?
Do not alternate medications unless instructed by a healthcare provider, to avoid dosing errors.
Sources and References
Johns Hopkins Medicine – Fever Information
https://www.hopkinsmedicine.org/health/conditions-and-diseases/fever
WebMD – Fever: Causes, Symptoms, and Treatment
https://www.webmd.com/first-aid/fevers-causes-symptoms-treatments
NewYork-Presbyterian Health – Fever Overview
https://www.nyp.org/primary-care/fever
Centers for Disease Control and Prevention (CDC) – Dengue and Mosquito-Borne Disease
https://www.cdc.gov/dengue/
CDC – Rocky Mountain Spotted Fever
https://www.cdc.gov/rmsf/
CDC – Typhoid and Paratyphoid Fever
https://www.cdc.gov/typhoid-fever/
World Health Organization (WHO) – Yellow Fever Fact Sheet
https://www.who.int/news-room/fact-sheets/detail/yellow-fever
Mayo Clinic – Scarlet Fever Symptoms and Causes
https://www.mayoclinic.org/diseases-conditions/scarlet-fever/symptoms-causes/
Mayo Clinic – Valley Fever (Coccidioidomycosis)
https://www.mayoclinic.org/diseases-conditions/valley-fever/
American Academy of Pediatrics (HealthyChildren.org) – Fever and Children
https://www.healthychildren.org/English/health-issues/conditions/fever/
National Institutes of Health (NIH) – Fever Overview
https://medlineplus.gov/fever.html
