What component of the body's metabolism describes the energy required to maintain essential body processes such as respiration, circulation, and temperature regulation?

The correct answer is basal metabolic rate.

Explanation:

Metabolism includes the procedures that the body requires to function. The basal metabolic rate refers to the sum of energy per unit time, which an individual requires to maintain the function of the body at relaxation. Some of these procedures are blood circulation, breathing, growth of cell, the controlling temperature of the body, contraction of muscles, and brain and nerve function.  

Basal metabolic rate influences the rate at which an individual burns calories and eventually whether that person maintains, loses, or gains weight.  

your body is trying to warm itself up. or more precisely, sensors in your skin send messages to your brain to generate heat to your body.