Core body temperature refers to the temperature of the internal environment of the body. This includes organs such as the heart and liver, and the blood. Learn more about core body temperature, and take a short quiz at the end.
What Is Core Body Temperature?
Temperature is an important factor to our general comfort. For the most part, we don’t like to be too hot or too cold.
Fortunately, in most circumstances we can regulate our body’s surface temperature by changing environmental factors. Feeling chilly? Put on sweater or bundle up under a blanket. Too hot? Time to crank the air conditioner or take a dip in the pool. But, the importance of maintaining the right body temperature goes beyond simply being comfortable.
It probably comes as no surprise that our bodies must maintain the right internal temperature in order for us to stay alive. This is known as our core body temperature, and it is exactly what it sounds like: the temperature of the inner parts of your body. This would include vital organs, such as the heart, liver and kidneys, and the blood.Although core body temperature fluctuates some, it must always be right around 98-100 degrees.
If this number varies too much, systems cannot function properly, and our health is in danger. In this lesson, we’ll take a closer look at core body temperature and the ways in which it is measured.
Core Temperature Regulation
We have already established that we can regulate our own temperature pretty well. Our senses tell our brain that we are too hot or cold, and we consciously make adjustments.
This works pretty well under normal circumstances. But while we are adding and removing layers, our bodies are also making changes. We have a built-in system that is continually striving to keep internal conditions constant.
A part of the brain known as the hypothalamus is responsible for maintaining homeostasis, a constant internal environment, in the body. It acts as an internal thermostat, working hard to maintain the right core temperature. Because of signals sent by the hypothalamus, our bodies make automatic responses to heat and cold. So, how does this system work?Our bodies are full of tiny heat sensors. These sensors send signals to the hypothalamus, alerting it to changes in temperature.
Say, for example, you are exercising on a hot day. You have consciously taken off some layers but you are still hot. Now the hypothalamus steps in. It receives word that the body is heating up and sends a signal to begin the production of sweat in order to cool the body down. You become red-faced as your blood vessels dilate, causing your skin to release heat.Likewise, maybe you are walking through the snow on a chilly winter day and you’ve left your coat at home.
Again, sensors alert the hypothalamus to your chilly extremities. Your hands and feet become cold first, as the body is attempting to retain the most heat in your core. A prompt is sent to your muscles, which become tense and start shivering. This is your body’s way of attempting to warm you up, all in order to maintain that constant core body temperature. Now let’s take a look at how core temperature is measured.
Core Body Temperature Measurement
You’ve probably had your temperature taken many times in your life. Maybe you had a parent who could place a hand on your forehead and know in an instant whether or not you had a fever. Our surface temperature can be obvious to the touch as our skin heats up or cools down. But upon feeling a warm forehead, chances are mom pulled out the thermometer and popped it under your tongue. Was this a measurement of your core body temperature? And how accurate, if so?Taking an exact measurement of core body temperature involves more than just using a thermometer under the tongue. However, for a relatively healthy person, conventional methods of measuring temperature give an accurate enough reading.
Taking temperature under the tongue usually gives a good reading because it is close to the lingual artery. Other locations that are considered fairly accurate temperature readings are the ear canal and the rectum.For individuals that may be critically ill in the ICU, however, this may be a different story. Core body temperatures that are either dangerously high or low can be life-threatening. In this case, the need may arise to get a more accurate core body temperature reading. But clearly, a physician can’t simply put a probe into a person’s vital organs to take a core temperature.
So how do they take this measurement?There are two places that are typically used by medical professionals to get accurate core body temperature readings: the pulmonary artery and the bladder. These methods are invasive, meaning they have to get into the body parts in order to measure accurately. In order to do this, catheters with the ability to measure temperature are inserted into the pulmonary artery or bladder. This measures the temperature of the blood and urine in those locations, giving an accurate sense of general internal temperature.
Core body temperature is the temperature of the internal environment of the body. This is different than surface temperature, which fluctuates more depending on the external environment.
Temperature readings taken under the tongue, in the ear canal, and in the rectum are considered sufficient for healthy individuals. Critically ill patients may need more accurate temperature readings. In this case, invasive methods must be used. Special catheters with temperature probes are inserted into the pulmonary artery or bladder to get a core body temperature reading.