Author
Bowtie Team
Updated on
2025-08-05
Disclaimer: This article is translated with the assistance of AI.
Fevers hit everyone from kids to adults—it’s a rite of passage! But what’s the real threshold for a fever? Dive into the causes, symptoms, and smart ways to manage it, all explained by the Bowtie medical info team.
Understanding Fever: Causes and Symptoms
According to information from the Primary Health Care Office under the Food and Health Bureau Primary Healthcare Commission and the Family Health Service of the Department of Health , fever is not a disease but a symptom. 1
It indicates that your body’s immune system is functioning normally to fight off invading germs or viruses. During a fever, the body ramps up antibody production, boosts phagocyte activity, and speeds up circulation to combat pathogens. In such cases, body temperature typically ranges from 38.5°C – 40°C / 101°F – 104°F. 1
While having a fever, you might experience chills, feeling hot, sweating, headaches, muscle aches, joint pain, loss of appetite, dehydration, fatigue, or weakness. In cases of high fever, symptoms could include confusion, hallucinations, irritability, seizures, or convulsions. 2
What Temperature Counts as a Fever?
A fever means your body temperature is 0.58°C / 1°F or more above normal. So, if it reaches 38°C / 100.4°F or higher, it’s a fever; 39.5°C / 103°F or above is considered a high fever. Normal temperature varies by measurement method. 1
Plus, temperature can be influenced by age, weather, clothing, activity, vaccinations, and measurement method. Keep these in mind when checking if you or your child has a fever.
How to Measure Temperature? Method Accuracy Comparison
If you have a fever, measure your temperature every 4 hours to check if it’s subsiding. Here’s a comparison of methods and normal temperature ranges: 3
| Thermometer Type | Infrared Ear Thermometer | Digital Thermometer | |
| Measurement Site | Eardrum | Armpit | Rectum |
| Accuracy | Probe must be positioned correctly |
|
|
| Price | More expensive | Cheaper | |
| Convenience |
|
Easy to use | |
| Normal Temperature | 35.8°C – 38°C (96.4°F – 100.4°F) | 34.7°C – 37.3°C (94.5°F – 99.1°F) | 36.6°C – 38°C (97.9°F – 100.4°F) |
| Notes |
|
|
|
Additionally, traditional mercury thermometers are fragile and contain toxic mercury, so parents should avoid using them for temperature checks.
Real Story: Child Fever Management Tips
Fevers can be minor or serious, but they’re especially risky for young children! Kids have weaker immune systems, making them prone to infections and illnesses, which could even affect their development and growth. That’s why many doctors recommend hospital observation for sick toddlers.
| Mrs. Chan’s (pseudonym) son is 2 years old. One day, he suddenly developed a fever and diarrhea .
Amid the raging pandemic , Mrs. Chan was understandably worried and rushed him to St. Teresa’s Hospital for treatment! Fortunately, it was just gastroenteritis , and after a few days of hospital treatment and observation, he was fine. The 5-day, 4-night hospital stay cost HK$47,268 . |
Right after her son was born, Mrs. Chan had already purchased Bowtie VHIS Flexi Regular for him, providing HK$600,000 in annual hospitalization coverage. After discharge, she reached out to Bowtie for help with the claim, which reimbursed nearly 81% of the costs.
Imagine if Mrs. Chan hadn’t insured her son—she’d have to foot that hefty hospital bill herself. Of course, parents could take kids to public hospitals for much cheaper care! But during a pandemic, public services are limited. With health insurance , you can take your child to a private hospital for treatment without worrying about the expenses!
- * The above cases are real cases for reference purposes only. Actual medical expenses will depend on the doctor’s recommendations and decisions based on the patient’s condition.
Causes of Fever
Sanatorium & Hospital ‘s publication mentions that most fever cases are caused by the common cold, or possibly due to bacterial or viral infections in the respiratory, digestive, or urinary systems. Additionally, fever could stem from immune system disorders like rheumatoid arthritis and lupus . 2
Infections are a common cause of fever in children, such as respiratory infections , gingivostomatitis, hand, foot, and mouth disease , bronchitis, pneumonia, urinary tract infections, middle ear infections, or tonsillitis. If a child develops a rash during a fever, it could be roseola, chickenpox, scarlet fever, or measles . If the fever persists and doesn’t subside, it might indicate serious conditions like Kawasaki disease, rheumatic fever, tuberculosis, encephalitis, or meningitis—parents should seek medical attention promptly. 1
When to Seek Medical Help for Fever?
Besides persistent fever, if a child experiences seizures, lethargy, refusal to eat, or dehydration, parents should seek medical help quickly and inform the doctor about any medications taken and medical history.
If the child’s temperature rises to 40°C (104°F) or higher, with breathing difficulties, severe cough, chest pain, pale or blue complexion, subcutaneous bleeding, or even coma, paralysis, stiff neck, swallowing difficulties, excessive drooling, severe vomiting, diarrhea, abdominal pain, back pain, or dehydration, parents should rush to the emergency room for treatment. 1,6
How to Manage Fever at Home
If the child’s fever isn’t severe, parents can manage it at home with these key care tips: 1,8
- Check and record the child’s temperature every 4 hours.
- Continuously monitor the child’s condition, including mental state, breathing, circulation, urination, bowel movements, vomiting, abdominal pain, rashes, throat or ear pain—inform the doctor in detail if seeking care.
- Strictly follow the doctor’s instructions for fever-reducing medication to alleviate discomfort, which can indirectly boost appetite and prevent dehydration.
- Fever and sweating cause fluid loss, so ensure the child drinks plenty—6 to 8 cups daily. Seek medical help immediately if dehydration signs appear.
- Keep the child at home, avoiding school and exercise, and ensure ample rest.
- Fever slows digestion, so avoid greasy or hard-to-digest foods, but no need to cut portions—opt for smaller, frequent meals.
- Warm baths, sponging with warm water, fever patches, or ice packs won’t reduce fever but can ease discomfort. Avoid cold water or alcohol rubs.
- Dress the child in long-sleeved, loose clothing during fever; avoid overheating or chilling. Use cotton for sweat absorption and change when damp.
- Maintain room temperature at 22°C-26°C, open windows for air circulation. Use fans or AC, but don’t direct airflow at the child.
At the clinic or hospital, the doctor will identify the fever’s cause based on history and examination—most are self-resolving viral infections.
In such cases, they’ll prescribe fever reducers or symptom relievers; for severe infections, antiviral drugs or antibiotics may be given, and hospitalization suggested for further checks if serious.
How Bowtie Insurance Protects You
Children’s fevers can range from mild to serious, potentially requiring hospitalization for checks and treatment. If parents want their kids to have inpatient medical coverage, consider Bowtie Pink VHIS , which offers reimbursement-based medical protection. Eligible medical expenses can be fully reimbursed* . Get a quote for yourself or your family now.
- * Full reimbursement means no sub-limits on claims and applies only to specified benefit items. Payable benefits are subject to the remaining deductible (if applicable), annual benefit limit, lifetime benefit limit, and other limitations including reasonable and customary charges, pre-existing conditions, designated hospital list in Mainland China, and treatments in the US. For detailed product terms and conditions, product risks, and exclusions, please refer to the relevant product website and policy.
Can Fever “Damage the Brain”?
Some patients develop fever due to encephalitis or meningitis, where the brain can indeed be damaged by bacterial infection. Since encephalitis or meningitis also causes fever, people often link high fever with “brain damage.” In fact, ordinary fevers generally do not harm the brain. 1
Is High Fever More Dangerous Than Low Fever?
In reality, the severity of the illness isn’t directly related to body temperature; the key is the underlying cause.
Does Fever Just Need Fever-Reducing Medicine to Heal?
Actually, relying solely on fever-reducing drugs treats the symptom but not the root cause. The thorough approach is to target the underlying condition causing the fever. 1
Should You Sweat Out a Fever by Bundling Up?
Some believe that wearing jackets, coats, or covering with thick blankets to sweat out a fever helps. In truth, this not only doesn’t reduce the fever but can actually raise body temperature. 4,6
References
- 1 衞生署. “兒童健康攻略.” 衞生署, 2017
- 2 養和醫院 “養和之道第三十六期” 養和醫院, 2010
- 3 Department of Health Medical Device Division. “Proper Use of Thermometers to Measure Body Temperature.” Department of Health Medical Device Division
- 4 衞生署 “發燒的護理” 衞生署, 2023
- 5 NHS. “High Temperature (Fever) in Adults.” NHS, April 6, 2020
- 6 NHS . “Fever in Children.” NHS, December 21, 2020.
- 7 Mayo Clinic. “Fever – Symptoms and Causes.” Mayo Clinic, May 7, 2022
- 8 Department of Health Family Health Service. “Family Health Service – Parenting Series 4: Managing Your Baby’s Fever.” Department of Health Family Health Service
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