Understanding and Managing Fever: What You Should Know

People in our country are quite familiar with fever and the use of fever-reducing medications. Many experience fever relatively often.

What Causes a Fever?

Fever is a natural response when the body is fighting off foreign invaders such as pathogens or inflammation. The hypothalamus in the brain increases body temperature to create an environment unfavorable for viruses or bacteria growth and to enhance the immune system. Fever also signals that something abnormal is occurring in the body. Causes of fever range from common viral infections like cold or flu, bacterial infections, autoimmune disorders, medication side effects, vaccination responses, to certain cancers. Chronic stress may also contribute to inflammation and fever.

What Temperature Is Considered a Fever?

A fever is indicated when body temperature exceeds 36.2–37.5°C. Fever levels can be classified as:

• Low-grade fever: 37.6–38.3°C
• Moderate fever: 38.4–39.4°C
• High fever: 39.5–40.5°C
• Very high fever: above 40.5°C

Temperature can be measured in various ways, with oral (under the tongue) and ear methods generally being most accurate.

How to Reduce a Fever

The key is to identify the underlying cause to properly address it. Ways to reduce fever include:

• Sponging the body with warm water on folds such as armpits, neck, and groin
• Resting in a well-ventilated room
• Avoiding hot or stuffy rooms
• Wearing light clothing to help heat dissipation
• Drinking plenty of fluids and electrolyte solutions

Special Care for Children

Young children need careful attention, as high fever may cause seizures. Frequent sponging to cool the body is important.

Medication

• Paracetamol is the first choice for fever reduction if no allergies or liver problems exist.
• If paracetamol is ineffective or cannot be used, ibuprofen, an NSAID, may be considered for both children and adults.

Recommended Dosages:

• Children: 5–10 mg/kg per dose every 6–8 hours (max 40 mg/kg/day)
• Adults: 200–400 mg per dose every 6–8 hours

Consult a pharmacist for accurate dosage.

Ibuprofen Precautions:

• Avoid if allergic
• Higher risk of allergic reactions than paracetamol
• Take after meals to prevent stomach irritation
• Risk of kidney damage, especially in elderly or at-risk patients

Stop medication and seek medical help if rash or breathing difficulties occur.

When to See a Doctor

• Fever over 38.5°C lasting more than 2 days
• Accompanied by lethargy, vomiting, or breathing difficulty

Thai Traditional Medicine and Herbs

Traditional Thai remedies like Andrographis (Fa Talai Jone), Tinospora (Borapet), and Chandanalila have been used to reduce fever, some supported by research.

Summary

Fever is a common symptom caused by various factors. Paracetamol is the recommended medication if no allergy exists. Complement with other methods like sponging and fluid intake. If symptoms persist beyond 2–3 days, consult a doctor promptly, especially during dengue outbreaks, to avoid serious complications.  

Assoc. Prof. Dr. Natthada Areepian, RPh Assoc. Prof. Dr. Bodin Tiwsoowan, RPh Faculty of Pharmaceutical Sciences, Chulalongkorn University