The Internal Adjustment System: A closer look
Let’s look at the body as a self-regulating machine to see how it functions to maintain body temperature. Its ability to do that is dependent upon the energy and other inputs required. They must be available. When the system is working the body is able to perform the tasks and produce the outputs required of it. As with all other mammals, a primary function – one necessary for survival – is maintaining its body temperature. For humans typically that is 98.6°F. Humans have developed a bodily system that enables it to maintain that temperature. They are able to do that in spite of considerable variation in the temperature in the external environment. Let us define what we will call the ideal external temperature. It is one that requires the body to expend the least amount of effort and energy to maintain its internal temperature. Let’s assume that it is 68°F. Any lower outside temperature requires more energy. As does any higher one to cool the body off.
Since the normal body temperature is higher than the optimal outside one, it is always necessary for the body to expend energy to maintain bodily temperature. That internal processing mechanism is always in place, always functioning. In order to function, it requires the necessary flow of inputs. That includes energy and whatever else it takes to keep the body temperature at 98.6ºF. That flow of energy can come from a stock stored within the body or from the contemporaneous flow of inputs. They, in turn, must be processed and stored so that the energy is available when needed. Additional inputs are required to adjust to any external temperature either below or above the optimal one. For example, if the temperature falls below 68° a warm cup of soup or a sweater helps. So does lying in the sun. If it goes above that, getting into lighter clothes or standing in front of a fan helps. Since additional energy is required to make those adjustments, it too has to be stored in the body or be provided by adding inputs. Variation in external temperature is a daily occurrence – ordinarily it’s warmer in the day and cooler at night. The bodily system has developed mechanisms for adjusting to it. The primary one is our ability to store energy and get more inputs to replenish it.
The body has also developed feedback mechanisms to help adjust to temperature variation. Some are internal to the system, others are signals for action. When the external temperature is “too hot” the body sweats, promoting cooling. When you “feel warm” you shed clothing. When the temperature falls, the body signals you with cold feet and hands, chills, shakes and shivers. That lets you know that it’s time to put on more clothes. Those actions require the expenditure of additional energy. Both responses make you feel more comfortable. You’ve made an adjustment to the environment. Not everyone is exactly the same. For some their “normal” or typical temperature may not be 98.6º but something a little higher or lower. Moreover, it can also vary at different times in the day or during the month. That is how the bodily system works to maintain its internal temperature when it is working as it should. In order to do that a flow of energy and inputs are required. Without them neither the internal temperature adjustment system or the external one – the bodily actions designed to improve one’s condition – function as well as they could. As a result one’s ability to perform tasks can be impaired. There are also times when one’s temperature rises as part of appropriate functioning, that is the body’s way of fighting infection. It is a normal reaction. However, a high fever can get out of control and be life threatening. There are also times when the temperature control mechanism malfunctions. That can be life-threatening as well. For the most part and most of the time that mechanism works well. It allows the human body to maintain its internal temperature and enables us to perform our tasks and functions.