Why Do Doctors Put a Baby Hat on a Baby When It's Born?

You may barely catch a glimpse of your newborn baby’s head and hair before the delivery room nurses place a hat on his tiny head. A baby’s immature little system makes knit hats a necessity, so many hospitals have adopted hats for newborns as standard protocol. If you’re lucky, the hospital might let you choose your baby’s first cozy hat.

Excessive Heat Loss

A newborn’s head makes up 21 percent of the total body surface area, the March of Dimes states. Newborns also have a low percentage of body fat, states a care article published by the Presbyterian Hospital of Dallas 1. Heat loss can occur for a newborn by escaping through the body surface, through evaporation and by cooler surfaces or hands touching her skin. Because of the large ratio of head to body, it’s important to keep the newborn’s head covered.

Preventive Measures

Covering the head with a hat immediately after birth works effectively for reducing heat lost through body surface. In a study performed with heated mannequins, researchers compared a heated mannequin with a hat and one without a hat. The mannequins wearing hats experienced an average of 18.9 percent less heat loss than mannequins without hats, states authors of “Head Insulation and Heat Loss in Naked and Clothed Newborns Using a Thermal Mannequin,” published by Medical Physics Online in June 2002 2.

Monitoring Baby’s Temperature

In the first hours after birth, medical professionals will monitor a newborn to ensure he stays warm and to ascertain that the baby is regulating body temperature. Nursery staff dress a baby with a hat, diaper, undershirt, one swaddling blanket and a second blanket to cover the baby in the bassinet. Staff generally take the baby’s body temperature every 30 minutes until the baby maintains minimum body temperature for at least two hours. If the baby has difficulty maintaining body temperature, staff may place the newborn in a warmer.

Keeping Baby Warm After Discharge

Parents receive instructions for keeping a newborn warm after discharge. Babies feel colder faster than adults feel it. During baths, dry the baby quickly to prevent heat loss and place a hat on her head to minimize heat loss. Do not overdress a newborn, but in situations where a draft or a breeze blows on the baby, cover her head to keep her warmer.