Thermogenics
Thermogenic means tending to produce heat, and the term is commonly applied to drugs which increase heat through metabolic stimulation, or to microorganisms which create heat within organic waste. Approximately all enzymatic reaction in the human body is thermogenic, which gives rise to the basal metabolic rate.
In bodybuilding, athletes wishing to lose fat purportedly use thermogenics to increase their basal metabolic rate, thereby increasing their energy expenditure. Caffeine and ephedrine are commonly used for this purpose. 2,4-Dinitrophenol is a very strong thermogenic drug used for fat loss; it will give a dose-dependant increase in body temperature, to the point where it can induce death by hyperthermia. It works as a mitochondrial oxidative phosphorylation uncoupler, disrupting the mitochondrial electron transport chain. This stops the mitochondria from producing adenosine triphosphate, releasing energy as heat.