A baby's temperature while in the womb remains constant at about the same body temperature as the mother's, which is about 99.86 degrees Fahrenheit, according to Birth.com. The website further reports that the common body temperature for a newborn baby is about 96.8 degrees Fahrenheit.
Regulating Body Temperature
A newborn baby is unable to regulate his body temperature because he cannot shiver or sweat other than from the sweat glands in the feet, hands, head and neck. Newborns will revert to a fetal position in order to keep warm if they do not receive a cloth wrap upon birth. The main source of a newborn baby’s body heat is his baby fat, or brown adipose tissue, which accounts for between 2 and 7 percent of the newborn baby's body weight at birth, according to Birth.com.
Problems With Body Temperature
A doctor or caregiver may place the newborn baby in an incubator for between 12 and 24 hours if the baby’s body temperature is lower than normal until her temperature reaches a healthier level. Newborns who weigh less then 6 lb., 3 oz. may require additional care, such as a fluid drip or tube feeding, according to Birth.com.
The drop in temperature from within the mother's womb into a delivery room can contribute to excessive heat loss in a newborn baby. The evaporation of amniotic fluid from the newborn baby’s skin can also contribute to the newborn’s loss of body heat. A room that receives cool drafts from air conditioning vents, from a fan or from an open door can further cause rapid heat loss. Birth.com refers to this as heat loss by convection. The newborn baby can also lose body heat if his skin touches cooler objects or surfaces such as a caregiver's cold hands, a cool towel or an examination table.
Caregivers should ensure that there are no air drafts in the room and should wipe the baby dry with a towel moments after birth. Birth.com suggests that a newborn baby should receive immediate skin-to-skin contact with the mother's warm chest. Place a warm blanket or towel outside the newborn's body, as well as a bonnet or beanie on the newborn baby's head.
Taking a Newborn's Temperature
Sutter Health recommends taking a newborn baby's temperature either under the arm or in the rectum. Use a towel to dry the area beneath the newborn baby's arm, and press the thermometer between the newborn’s arm and the side of her body. To take a rectal temperature, coat the end of a blunt thermometer with petroleum jelly, and insert it gently into the baby's rectum no farther than 1/2 inch. Avoid using an ear thermometer to take the temperature of a newborn baby because the newborn’s ear canals are wet and can contribute to an incorrect temperature reading. Sutter Health cautions against taking your baby's temperature regularly and advises that you take it only when you believe she is sick.