Hmm...it's been a while since I've sat through a biochemistry class, so I may be wrong, but after reading the article I am reminded of natural and synthetic uncouplers.
Brown fat contains a lot more mitochondria, frequently referred to as the "powerhouse" of the cell, and these tiny organelles use
oxidative phosphorylation to create more ATP (energy molecule), basically by transporting protons across the mitochondrial membrane to generate ATP.
There is a natural uncoupler protein found in the mitochondria of brown fat which uncouples phosphorylation from oxidation. In this process, instead of generating ATP molecules to be used for energy, you get heat.
A famous synthetic uncoupler, 2,4-Dinitrophenol, was and is still illicitly used as a weight-loss drug. It has caused a number of deaths due to overheating (hyperthermia). Thermogenics, they are called in Brazil, I don't know if it's the same abroad. It also uncouples the process to get the same effect in white fat cells.