Uncouplers:

Some  chemicals,  like  as  2,4-dinitrophenol (DNP),  act  as  uncoupling  agents, which is, when added to cells they stop ATP synthesis but electron transport since continues  and so oxygen  is still consumed.  The motive is that DNP and other uncoupling agents are lipid-soluble small molecules that can bind H⁺ ions and transport them across membranes an example they are H⁺ ionophores. Electron transfer occurs  and pumps out H⁺ ions across the inner mitochondrial  membrane but  DNP  in the  same  membrane  carries  the  H⁺ ions  back  into  the  mitochondrion and  preventing  creating  of  a  proton  gradient.  Because no proton gradient established no ATP can be made through oxidative phosphorylation. Rather the energy consequent from electron transport is released as heat.

The production of heat through uncoupling is known as nonshivering thermogenesis. It is very important in certain biological situations.  For instance, uncoupling occurs generally in brown adipose tissue. These tissues are rich in mitochondria and the inner mitochondrial membranes of that contain a protein known as thermogenin or uncoupling protein. Thermogenin permits H⁺ ions to flow back into mitochondria without having to enter through the ATP synthase and so uncouples oxidative phosphorylation and electron transport, producing heat.  The importance of this natural phenomenon is in which brown adipose tissue is found in sensitive body areas of some newborn animals (involving humans) where the heat production gives protection from cold conditions.  Additionally, thermogenesis through brown adipose tissue plays a role in maintaining body temperature in the hibernating animals.