One method used by newborn mammals to generate heat is referred to as nonshivering thermogenesis. this method utilizes a protein channel called which is present in high levels inside the mitochondria of .

One method used by newborn mammals to generate heat is referred to as nonshivering thermogenesis. This method utilizes a protein channel called thermogenin which is present in high levels inside the mitochondria of brown adipose tissue.

Explanation:

Thermogenin forms a proton channel in the inner mitochondrial membrane in the brown adipose tissues. Most of the newborn mammals have these brown adipose tissues. In these tissues, the oxidation of nutrients do not produce ATP but generate heat. The heat is used by the newborn to maintain the warmer body temperature. The process is called nonshivering thermogenesis.