Chapter 13 - Human Thermoregulation

Abstract

Publisher Summary This chapter presents an overview of human thermoregulation. Skin temperature varies over the body because of exposure to the environment and change in the circulation of the blood primarily because of the thermoregulatory responses. The temperature of the fingers and toes varies most—up to 30°C—and that of the proximal part of the limbs and the trunk less—3° to 4°C). Regulation of body temperature is different in newborns than in adults owing in part to the immaturity of the infant's nervous system. The effect is even more pronounced in premature infants. Babies have a relatively higher ratio of surface area to mass than adults, and they have difficulty thermoregulating in both hot and cold environments because heat exchange with the environment is more rapid. Babies rarely shiver. They use the special characteristics of their highly calorigenic brown fat to produce large amounts of heat. Their sweat glands are immature and largely localized on the face and head. Premature babies, especially those born more than 8 weeks before term, do not sweat at all at birth.