Babies can lose heat rapidly, as much as four times more quickly than adults.
Premature and low birthweight babies usually have little body fat and may be too immature to regulate their own temperature, even in a warm environment. Even full-term and healthy newborns may not be able to maintain their body temperature if the environment is too cold. When babies are cold-stressed, they use energy and oxygen to generate warmth. By keeping babies at optimal temperatures, neither too hot or cold, they can conserve energy and build up reserves. This is especially important when babies are sick or premature.