At what age does an infant gain the ability to generate heat when needed?

At what age does an infant gain the ability to generate heat when needed?

• A. Birth
• B. 6 to 12 months
• C. 12 to 18 months
• D. 2 to 3 years

Answer: (C)

An infant’s ability to generate heat when cold comes from the development of shivering as a heat-producing response. Newborns rely mainly on nonshivering thermogenesis using brown fat, and their muscles aren’t yet able to generate heat rapidly through shivering. The ability to shiver and actively raise metabolic heat typically develops around 12 to 18 months, which is why that age range is the correct answer. By 2 to 3 years, this thermoregulatory mechanism is well established.

An infant’s ability to generate heat when cold comes from the development of shivering as a heat-producing response. Newborns rely mainly on nonshivering thermogenesis using brown fat, and their muscles aren’t yet able to generate heat rapidly through shivering. The ability to shiver and actively raise metabolic heat typically develops around 12 to 18 months, which is why that age range is the correct answer. By 2 to 3 years, this thermoregulatory mechanism is well established.