In infants from birth to 3 months old, an abnormal temperature--either too low or too high--can be a sign of something serious. A baby with a low body temperature may have a serious infection, according to MedlinePlus.com, and an infant with a fever requires an immediate call to the doctor. All parents should know which type of thermometer is most accurate, how to take an infant's temperature safely and the range of temperatures considered normal in an infant.
Today's parents have choices among thermometers. The older-style glass mercury thermometers are not recommend for infants because if the glass breaks, mercury vapors are released into the air, according to the Mayo Clinic. Newer choices include the forehead and ear thermometer, the pacifier thermometer, and digital thermometers designed for oral, rectal or armpit use. Temperatures taken in the armpit or with a pacifier thermometer are the least accurate.
Taking an Infant's Temperature
"The most accurate way to take a child's temperature is to use a digital thermometer rectally or orally. Rectal temperatures provide the best readings for infants," reports the Mayo Clinic. Place your infant on her back and lift her legs. For infants up to 3 months, lubricate the tip of a rectal digital thermometer and insert it 1/2 to 1 inch into her rectum. It should slide in easily, but if you feel any resistance, stop. Hold it in place until the thermometer beeps or otherwise signals that it is done. Remove it gently and check the display.
An infant up to 3 months old has a normal body temperature range of 97 to 100.4 degrees Fahrenheit, 36 to 38 degrees Celsius, according to the American Academy of Pediatrics. Temperatures both higher and lower than this range are a cause for concern.
A baby 3 months or younger is considered to have a fever when his temperature is 100.4 degrees Fahrenheit, or 38 degrees Celsius, or higher. With older children, parents are advised to watch a feverish baby's behavior before calling the doctor. If the older baby is playing and eating well, for example, he probably doesn't need immediate medical attention. However, with infants up to 3 months, BabyCenter says to call the doctor immediately if he has a fever because he could have an illness.
Babies who sleep in a room that causes them to become too hot are at an increased risk for Sudden Infant Death Syndrome, commonly called SIDS, according to the Utah Department of Health. It recommends against putting your baby to sleep with too much bedding or clothing and to use a fan, as well-ventilated rooms reduce the risk of SIDS by up to 70 percent. Some signs that your baby is too hot include damp hair, a heat rash, fast breathing, fever and sweating.
Never give aspirin to an infant with a fever, as it can cause Reye's syndrome, a disorder than is potentially fatal. In addition, don't give ibuprofen to babies under 6 months, according to the Mayo Clinic.