Keeping your baby warm enough and worrying that she's too cool or even too warm is natural as she is unable to regulate her own body temperature during the first few weeks of life. According to Dr. David Geller of the Babycenter, you know she is not too warm or too cold if she is sleeping comfortably, eating well and not irritable or fussy. Take her to her pediatrician if you are concerned about body temperature.
During pregnancy, your baby's temperature is regulated inside the womb. A newborn is less able to regulate his temperature because he is unable to shiver to warm himself. His main method of heat production is using brown adipose tissue -- or BAT -- a fatty tissue that is created in the womb. The problem is that using BAT takes an extreme amount of energy, so he relies on you for warmth so he doesn't become too stressed and tired. When he is calm and lying down, feel his hands, feet and forehead to ensure they are not cold. As a general rule, Dr. Geller indicates that an infant needs only one more layer of clothing than you in the same temperature.
A normal temperature for your infant is 96.8 to 98.6 F, according to Birth. A temperature lower than 96.8 F warrants a call to her pediatrician because she needs to be warmer. A temperature above 98.6 to 99.5 F is a low-grade temperature that could be due to your baby being dressed too warm or in a warm environment. Watch her temperature, but you can try removing blankets or clothing items. An elevated temperature is 99.5 to 100.4 F, and a fever is a temperature over 100.4 F. Call her pediatrician if your infant has an elevated temperature or a fever.
Methods of Heat Loss
Your baby can lose body heat by evaporation. For example, when your baby comes out of the tub, the surrounding air evaporates the water. According to Birth, heat loss can occur quickly because babies have large skin surfaces in which to lose heat. In addition, a baby's head makes up a big portion of this area. Dry your baby quickly, put on a hat and make sure there are no open windows or drafts in the area where he is getting a bath. Your baby can also lose heat when his body comes into contact with a cool surface because it takes heat from his body. Make sure a surface you lay your baby on is covered or padded.
How to Take Temperature
Always use a digital thermometer to take your infant's temperature as mercury thermometers are potentially toxic and should be removed from your home, advises the American Academy of Pediatrics' Healthy Children. Talk to your pediatrician about the ideal way to take your infant's temperature, but the American Academy of Pediatrics recommends taking a rectal temperature if your baby is 0 to 3 months and rectal or axillary -- under the arm -- if your baby is older than 3 months. You can also use a tympanic, or ear thermometer, but it needs to be placed in the ear correctly to provide accurate results. Ask the pediatrician for advice.