There is a certain limit to the body's automatic temperature regulation. Wear less clothes and have a low body temperature when it is cold. Through the secretion of adrenaline, the human body accelerates energy consumption and temporarily raises body temperature.
But this process is only short-term, and it mainly consumes sugar, not fat. Only by increasing the amount of exercise during freezing will you consume fat.
If the body temperature is kept low for a long time, the body will gradually convert some sugar into fat, which is a physiological behavior of self-protection evolved by warm-blooded animals and cannot be controlled by itself. Moreover, people with long-term low temperature will subconsciously consume a lot of high-calorie food when eating, which will also promote fat accumulation.