Energy balance

Brown adipose tissue (BAT) thermogenesis is a physiological mechanism that increases energy expenditure through non-shivering thermogenesis, primarily activated by cold exposure and sympathetic nervous system signaling.

Your body has a hidden calorie-burning system called brown fat that activates when you are cold. While you don't need to freeze yourself, keeping your living environment slightly cooler or exposing yourself to mild cold can help activate this tissue to burn more energy. This is a natural physiological response, not a supplement or drug.