Fever

Understanding Fever in Infants: When to Worry and When to Wait
Guidance for Parents from Your Pediatric Care Team

Introduction
Fever is one of the most common reasons parents bring their infants to the doctor. While a rise in temperature can be alarming, it’s often the body’s natural way of fighting infection. Still, in infants—especially those under 3 months old—fever can signal something more serious and needs careful evaluation.

At our clinic, we’re here to help you understand when a fever is a cause for concern and what steps to take to keep your baby safe and comfortable.

What is a Fever?
A fever is typically defined as a rectal temperature of 100.4°F (38°C) or higher. It’s important to use a digital rectal thermometer for infants to get the most accurate reading.

Common Causes of Fever in Infants

• Viral infections (like colds, flu, or roseola)
• Bacterial infections (such as urinary tract infections, pneumonia, or ear infections)
• Immunizations (low-grade fever for 24–48 hours is normal after vaccines)
• Overheating (from over-bundling or warm environments, not true fever)

When to Call the Doctor Immediately
Always contact your healthcare provider or seek medical attention if:

• Your infant is under 3 months oldand has a fever of 100.4°F (38°C) or higher, even once
• The baby is very sleepy, hard to wake, or not feeding well
• You notice difficulty breathing, persistent crying, or a seizure
• There are signs of dehydration(dry mouth, no tears when crying, or less than 3 wet diapers in 24 hours)
• The baby has a rash with the fever, especially one that doesn't fade with pressure
• The fever lasts more than 3 daysin infants older than 3 months

What You Can Do at Home
If your baby is older than 3 months and appears generally well:

• Keep your baby hydrated: Continue breast milk or formula frequently.
• Dress your baby in light clothing: Avoid over-bundling.
• Use fever reducers only if recommended: Acetaminophen (Tylenol) can be given to babies over 2 months; Ibuprofen (Motrin) is generally safe for babies over 6 months. Always consult your provider for proper dosage.

How We Evaluate Fever in Infants
At your visit, we will:

• Take a full history and perform a physical exam
• Possibly order blood, urine, or other lab tests
• Decide if observation, medication, or hospital evaluation is needed—especially for babies under 3 months

Prevention Tips

• Handwashing is crucial for anyone handling the baby
• Limit contact with sick individuals
• Ensure your baby is up to date on immunizations
• Breastfeeding can provide added protection through maternal antibodies

Trust Your Instincts
As a parent, you know your baby best. If your infant seems “off” or you feel something isn’t right—even if they don’t have a high fever—please call us. It’s always better to be cautious, especially in young babies.

We’re Here to Help
If your baby develops a fever, don’t panic—you’re not alone. Sima Stein, MD clinic is here to guide you through every stage of your child’s health. Contact our office anytime you have concerns about your infant's temperature, feeding, or behavior.

Need care now?
Schedule an appointment with Dr. Sima Stein, MD (San Jose) here: Book Online with Dr. Stein yelp.com+11doctor-stein.com+11doctor-stein.com+11