If your child's body temperature reaches 100.4 degrees Fahrenheit, he has a fever, according to the Children's Hospital Boston. Fever is the body's way of trying to rid itself of infection. Low level fever might only last a few days and act as a stage in the recovery process. However, high fever levels for a long period can cause serious health problems. See a doctor if a very young child has a high fever.
Method
You can take your child's temperature in three ways. Fever levels differ slightly with each method, according to the University of Maryland Medical Center. For example, an oral thermometer that reads 99.5 F means your child has a fever. A rectal reading of 100.4 F also equates to fever level. If you use an under-arm thermometer to check your child's temperature then look for a 99 F reading. This signifies a fever.
Common Levels
Children older than 3 months of age with fever levels between 100.4 and 102 F usually don't need medical attention, according to KidsHealth. This low-grade fever may break after a short period. When a fever climbs above 102.2 F in a toddler up to 3 years old, call your doctor right away. Older children usually tolerate the low-end fever, though you'll need to take care of your child until he's strong again. In any case, if fever occurs alongside symptoms such as vomiting, listlessness, bloody stools or similar conditions, speak to your doctor.
Dangerous Levels
While all high body temperatures can lead to health problems, some fever levels can mean serious and immediate threats to a child's health. As a fever reaches 107.6 F, it can lead to brain damage. However, this level of fever rarely occurs naturally unless you wrap your baby too tight, leave your child in a hot car, increase the room temperature significantly or otherwise make conditions extra hot. Take a baby with a rectal fever temperature of 100.4 F or more straight to an emergency room as babies are more sensitive to fever.
Considerations
As a general rule for older children, anything over 105 F is classed as a high fever level with a risk of bacterial infection. When measuring temperatures, aim for the most reliable possible reading. Ear thermometers don't give an accurate fever level reading for babies under 6 months, according to the Seattle Children's Hospital Research Foundation. Be watchful for other symptoms when you notice your child has a fever. Sometimes fever acts as the forerunner for another problems such as diarrhea or coughing.
