A fever is a temperature greater than or equal to 100.4º F or 38º C. Fever in children is very common. Fever is a normal body response that helps the body fight infections.

The information in this video is for otherwise healthy children older than 3 months. If your child is younger than 3 months old, or has a health problem that makes infection more likely, always call your child's doctor for advice when your child has a fever.

Your child's temperature is not the most important thing to monitor when your child has a fever. Most of the time you won't even need to take your child's temperature. Instead, pay attention to the symptoms your child is experiencing along with the fever.

These are normal symptoms: Faster heart rate and breathing; shivering; cold hands and feet; head and body aches; tired and fussy; poor appetite. You don't necessarily need to call the doctor if your child has these symptoms.

More on Fever in Healthy Kids

These are abnormal symptoms: Extremely sleepy or irritable; trouble breathing; rashes; pain, redness or swelling in one area (like a sore throat or a red, swollen knee); drinking very little or not at all; severely decreased urination; fever lasting longer than 3 days; seizure. You should call the doctor if your child has any of these symptoms, or if your instincts are telling you something isn't right.

Parents worry that a high fever will cause seizures or brain damage. A high temperature will not cause brain damage, and seizures due to fever are rare.