Thermogenesis is the process by which the body generates heat, primarily through metabolic activity. This occurs when the body burns calories to maintain its core temperature, especially in cold environments. There are two main types of thermogenesis: shivering thermogenesis, which involves muscle contractions, and non-shivering thermogenesis, which is mainly facilitated by brown adipose tissue. Non-shivering thermogenesis is particularly important in newborns and hibernating animals, as it helps them maintain warmth without muscle activity. Factors such as diet, exercise, and environmental temperature can influence thermogenesis, playing a crucial role in energy balance and weight management.