What is Fever?

Fever is usually, but not always, a sign of an infection in the body. The body has its own internal “thermostat” that regulates temperature, with a normal body temperature around 98.6°F (37.5°C).

When the body detects an infection or illness, the brain raises the body temperature to help fight it. Fever itself does not always require medical attention it depends on the child’s age and associated symptoms.

When is it Considered a Fever?

Your child is considered to have a fever if:

Rectal, ear, or forehead temperature: 100.4°F (38°C) or higher
Oral (mouth) temperature: 100°F (37.8°C) or higher
Underarm (armpit) temperature: 99°F (37.2°C) or higher

How to Take a Rectal Temperature

Rectal temperature is the most accurate method for measuring a young child’s body temperature.

The American Academy of Pediatrics recommends using digital thermometers and avoiding mercury thermometers due to safety risks.

Steps:

Use a digital rectal thermometer with a rounded tip
Clean the tip with rubbing alcohol or soap and water
Apply a water-soluble lubricant to the tip
Lay your baby on their stomach across your lap or a firm surface
- Alternatively, place them on their back and gently lift their legs
Hold your child steady with one hand
Carefully insert the thermometer about ½ inch into the rectum
- Stop if you feel resistance never force it
Hold the thermometer in place until it beeps
A reading of 100.4°F (38°C) or higher indicates fever

Common Causes of Fever

1. Viral Infections

Most common cause (cold, flu, etc.)
Fever may be the first symptom
Other symptoms (runny nose, cough, diarrhea) may appear later

2. Bacterial Infections

Urinary tract infections
Strep throat
Sinus infections

3. Newborn Fever (Serious)

Occurs in babies under 3 months
May indicate serious infections like sepsis
Requires immediate medical attention

4. Meningitis (Very Serious)

Infection of the brain and spinal cord lining
Symptoms: stiff neck, headache, confusion
Young children may be very irritable or unusually sleepy
Requires urgent treatment

5. Teething

Teething does not cause fever

Treatment and Care

1. Hydration and Comfort

Give plenty of fluids to prevent dehydration
Dress the child in light clothing
Avoid heavy blankets, as they can increase body temperature

2. Fever Medication

For 100–102°F (37.8–39°C): medication is usually not needed
Treat fever only if the child is uncomfortable

For fevers above 102°F (39°C):

Use acetaminophen (Tylenol) or ibuprofen (Advil)
Do not use both together
Avoid aspirin due to risk of Reye syndrome

Medications typically reduce fever by 2–3°F (1–1.5°C), not always to normal levels.

3. Lukewarm Sponging

Recommended if fever is above 104°F (40°C) and not responding to medication
Sponge for 20–30 minutes
Stop if the child starts shivering

Expected Outcome

Most fevers (especially viral) range between 101°F and 104°F (38.4°C–40°C)
Usually last 2–3 days
Generally not harmful

When to Call a Doctor

Seek medical care if:

Fever exceeds 104°F (40°C)
Any fever occurs in a child under 3 months old
Fever lasts more than 24 hours (under 2 years old)
Fever persists longer than 3 days (72 hours)
Child is:
- Lethargic or unresponsive
- Refusing to eat
- Having difficulty breathing
- Developing a rash

Signs of Dehydration:

Dry mouth
Sunken soft spot (in infants)
Fewer wet diapers

Emergency Situations:

Seizures
Severe symptoms or worsening condition

If you are unsure, it is always safest to consult a healthcare provider.

Areas We Serve

Epic Urgent and Family Care proudly provides fever evaluation and treatment services to patients across the following communities:

Neighborhoods

Arlington Heights, Buffalo Grove, Inverness, Barrington, South Barrington, Rolling Meadows, Wheeling, Prospect Heights, Deerfield, Mount Prospect, Lake Zurich, Glenview, Vernon Hills, Hoffman Estates, Schaumburg, Elk Grove Village, and Downers Grove.

ZIP Codes

60004, 60074, 60010, 60011, 60005, 60007, 60008, 60015, 60016, 60018, 60025, 60047, 60061, 60062, 60067, 60656, 60089, 60090, 60106, 60107, 60169, 60192, and 60193.