Fevers in children - when to call the doctor
2/5/2026 by Haley Sherburn, M.D.
Fever in children: When to call the doctor
A fever is a body temperature of 100.4°F (38°C) or higher. Fevers are a normal way the body fights infection. The most accurate way to check a temperature is with a rectal thermometer (for young children) or under the tongue (for older children). Underarm and forehead thermometers are less accurate and may miss fevers.
Common fever myths
Clearing up common myths can help parents feel more confident.
Myth: “Fevers are dangerous and can cause brain damage.”
Truth: Most childhood fevers do not harm the brain. Fever is the body’s natural response to infection.
Myth: “The higher the fever, the sicker the child.”
Truth: How your child looks and acts matters more than the number. Pay attention to drinking, breathing, and behavior.
Myth: “If my child feels warm, they definitely have a fever.”
Truth: Warm skin can happen for many reasons. Always check with a thermometer.
Normal fever patterns
Fevers often rise in the evening and fall in the morning. Most fevers in children over two months old who are up‑to‑date on vaccines are caused by viral illnesses and get better with home care.
Some fever patterns are not typical:
- Fever every day for five days or more
- Fever with drenching night sweats or unexplained weight loss
- Fever that improves, then returns after a few days (“second worsening”), which may suggest a new infection
- Fevers within 24 hours after vaccines can be normal.
Tips for monitoring your child’s fever
- Check less often.
- You don’t need to check unless your child seems uncomfortable or worse.
- Use the same thermometer method each time.
- Watch your child, not just the number.
- Behavior and hydration matter most.
- Keep a simple log of temperatures and medicines if the fever lasts.
- Don’t chase the number.
- Fever medicine is for comfort, not to make the temperature normal.
Home care
Help your child feel better by:
- Offering plenty of fluids
- Encouraging rest
- Using acetaminophen (Tylenol) or ibuprofen with weight‑based dosing
Avoid cold baths, alcohol rubs, and aspirin.
Red flags — time to call your doctor
Call your doctor or seek urgent care if your child has a fever and:
- Breathing problems (fast breathing, working hard to breathe, wheezing)
- Signs of dehydration (very little urine, dry mouth, no tears)
- Extreme sleepiness or constant irritability
- Severe or worsening pain
- Repeated vomiting or can’t keep fluids down
- A fast‑spreading or unusual rash, especially with neck stiffness
- You’re worried or something doesn’t feel right
Key Message
Most fevers in children over two months old are caused by viral illnesses and can be safely treated at home with supportive care.
Haley Sherburne, M.D. is a resident physician in Pediatric and Adolescent Medicine in Rochester, Minnesota. Following residency, she will start fellowship in pediatric hospital medicine at the Mayo Clinic.