Définition :
« The branch of biology that studies the functions and properties of tissues in living beings. »

A newborn baby does not have the ability to regulate its own temperature. The hypothalamus gland, which is responsible for regulating the body’s temperature, only becomes operational after a few months.

A baby’s skin is thin with very little fatty tissue. The skin surface area is three times greater than that of an adult and is highly developed in relation to its weight. This means that heat exchange between a baby and its environment is easier, making it more sensitive to external temperature conditions than an adult. Its body absorbs the cold and heat easier.

Producing its own heat and regulating its own body temperature are a major task for a baby, having enjoyed heat from its mother before birth.

As an illustration :

« The body’s thermal neutral zone lies at an ambient temperature of 28°C for adults and 32°C for newborns; the critical temperature (the ambient temperature below which an individual can no longer maintain their core temperature) is 1°C for adults, but 23°C for newborns. A newborn placed naked in a room heated to 23°C would therefore be in the same situation as an adult who had been asked to undress in a refrigerated chamber at a temperature of 1°C.” Dr S. Dalmas, CHRU (Regional Teaching Hospital), Lille. » Dr S DALMAS, CHRU Lille.