Brown fat gel packs

If I am correct in my understanding, stress can cause the body to produce additional brown fat, which is tricky to get rid of. I wonder if biologically, that mechanism helped prepare the body for difficulties, whether travel or famine, with the idea that the body would have dense stored energy. The tricky thing in a sedentary world is that while stress is real, the idea of needing stored calories to survive is, by and large, not true.