Healthy children often develop abnormal body temperatures while fighting off various forms of illness or infection. In most cases, these temperatures are temporary and do not indicate any cause for great concern. However, in some cases, your child may develop a temperature that is high or low enough to warrant a visit to a doctor.
To check your child's oral or rectal temperature, the Mayo Clinic recommends using a digital thermometer instead of a traditional mercury thermometer, which can break and expose your child to dangerous vapors. You can obtain the most accurate temperature readings for your young infant with a rectal thermometer. However, you can also use an ear thermometer for your infant or older child. In some cases, the presence of a small ear canal or ear wax may diminish an ear thermometer's accuracy. No matter the type of thermometer you choose, read and understand all included operating instructions.
If you take an oral reading, your child's normal temperature should be 98.6 degrees Fahrenheit, according to the American Academy of Family Physicians, or AAFP. If you take a rectal reading, your child's normal temperature should be 99.6 degrees Fahrenheit. For oral readings, doctors commonly define a fever as any temperature in excess of 99.5 degrees Fahrenheit. For rectal readings, doctors commonly define a fever as any temperature in excess of 100.4 degrees Fahrenheit.
Dangerously High Temperatures
If your child is less than three months old, contact his doctor immediately if he has a rectal temperature of 100.4 degrees Fahrenheit or higher, the AAFP reports. Since children this age can experience very rapidly developing health problems, contact a doctor even if your child seems otherwise fine. If your child is between the ages of three and six months, contact a doctor if his temperature reaches 101 degrees Fahrenheit or higher. If your child is six months or older, keep him under close observation if has a temperature between 102 and 102.9 degrees Fahrenheit. Call a doctor if his temperature persists for more than two days or increases. If your child in this last age group has a fever of 103 degrees Fahrenheit or greater, you should also seek medical assistance.
Dangerously Low Temperatures
In some cases, children may also develop hypothermia, a condition characterized by a body temperature that falls below 95 degrees Fahrenheit, the Mayo Clinic reports. Hypothermia is a medical emergency, and without proper treatment it can result in heart and respiratory failure, as well as death. Infants are at a particularly high risk for this condition, and you can help avoid potential problems by keeping your child well-covered during outside activities. If hypothermia occurs, seek medical assistance immediately.
A fever is not a reliable indication of your child's state of health, the Nemours Foundation notes. In some cases, viral infections such as colds can raise your child's temperature to high levels without actually causing any great amount of risk. In other cases, your child may develop quite serious infections without any increase in body temperature, or with actual temperature decreases. Infants, in particular, may experience these types of infections.