The cold turns on a process in our body that allows us to use fat to create heat.
Brown adipose tissue (BAT) is increased by cold temperature. This BAT uses white fat (Belly fat) as a source of energy to produce heat.
In other words, gently turning down the temeperature of the shower for the last 20-30 seconds promotes this process of fat burning. Also a nice kicker to this is the production of two feel good hormones for the brain (norepinephrine and dopamine).
For more information on the benefits of ‘cold thermogenesis’ check out Dr Mercola’s book ‘Fat For Fuel’