Hyperthermia and Homeostasis

Hyperthermia and Homeostasis

Definition of homeostasis is the attempt to keep equilibrium of the internal organisms despite the external environment. Homeostasis is everywhere in your body, think of the heart for a second. If you have a high blood pressure your cells send signals to your brain to slow the heart rate down to keep equilibrium, or if you have low blood pressure your heart will beat faster. Hyperthermia relates to homeostasis through numerous different systems in the body.
In order to diagnose this hyperthermia certain criteria of the body tissues are set. Generally we have signs and symptoms that we use to diagnose people with certain issues. Signs of hyperthermia can include increase in temperature, generally greater than 104F, tachycardia, tachypnea, coma, convulsions, and vomiting. Symptoms of hyperthermia can include dizziness, confusion or delirium. Hyperthermia can cause hyperthyroidism, brain injury, heat stroke, bacterial or viral infection. “The hypothalamus is the bodies major control center for homeostasis. Bathed in blood adjacent to the third ventricle of the brain, it receives information from the temperature of blood circulating around it and from temperature receptors in the peripheral nerves, spinal cord, and abdominal organs. Besides body temperature, the hypothalamus helps regulate the autonomic nervous system, water balance, and endocrine system function.” (Beard; 30) One example of the way your body attempts homeostasis when undergoing hyperthermia is when your body sweats, this mechanism is set up to cool down the skin. Energy is released through our muscles and in the expense of energy we create heat which allows our sweat glands to produce sweat. This message for your body to sweat and cool down is done so through messenger cells being sent to the hypothalamus, this part of the brain sends back a message to your outlying body systems. This is called a positive feedback system when the body is allowed to get over heated and then that change in the body sends positive feedback to the brain. Because at a certain point of heat exhaustion your body can become severely dehydrated from remaining in a hyper thermic state, you will see absence of sweat or no tears in people that are severely hyper thermic. So the bodies’ glands will become dry and you will not see the initial signs of over-heating in the body anymore.
At a microscopic level HSP’s (Heat Shock Protein’s) is a protein that is synthesized for overheating prevention. The protein can serve two different purposes. For this purpose of preventing overheating, they are released from inside the cell to serve as messenger cells. This messenger protein sends the signal to the immune system to kick in and cool down the body. HSP’s are more thoroughly discussed in an article from Current Protocols in Immunology.
Hyperthermia is directly related to the Basal Metabolic Rate. Basal Metabolic Rate “reflects the energy the body needs to perform only its most essential activities.” (Marieb and Hoehn; 833) So essentially the basal metabolic rate will increase with any additional needs, exercise, stress or illness on the body. When heat production becomes greater than heat loss through our body systems our body is a hyperthermic state. Our bodies’ homeostasis mechanisms to create heat loss is through radiation, conduction/convection and evaporation. We already discussed evaporation through our sweat glands. A new example is through radiation. Radiation is the heat or cool being absorbed by nearby objects, having a cool window open may help cool things down, removing warm objects can help reduce heat radiation. An example at a cellular level would be the body giving off a signal to the brain to release sweat glands and release heat from the muscles, but when your body does everything it can to cool down it starts to hold back water so you don’t dehydrate as fast as if you kept sweating. When you are losing water at a rapid rate your blood cells start to become sticky and slow down not allowing 02 to run through as easy. This will make your breathing increase and heart rate to increase trying to pump the 02 through just to get enough for maintaining homeostasis. Pretty soon if you do not get enough oxygen to your brain you start becoming disoriented and or just pass out. There are several different ways that the heat will affect you. Syncope, heat exhaustion, cramps, stroke and sometime you will swell.
There are several ways to cool a person down externally and internally. External ways of cooling the body include. Getting the person to shade and stripping their clothes off will help because it is cooler in the shade and less cloths allows the sweat to work as a cooling agent. Ice packs on the neck, arm pits, and groin will help with cooling faster, which are the areas that heat is retained or lost the most. Fans and misting there body with water will act as sweat and cool down the whole body as a mass. Ice bath would draw heat from them in a more rapid affect but down side is the person can go in to shock from cooling to fast. Internal cooling is more invasive then external but still is very effective. One way to internally cool someone would be blood cooling According the Center for Disease Control (CDC) the age group most at risk to experience hyperthermia or have a fatality related to hyperthermia is, “infants and children up to four years of age, and people 65 years or older.” Other groups are separated out not by age to define them as a high risk to have a fatality from hyperthermia these groups are “overweight, and people who are ill, or on certain medications.” A specific reason the age group of 65 years or older is at high risk to suffer fatality from hyperthermia is that they are less likely to sense and react to temperature changes. It’s a pretty normal social idea that old people always complain about being cold. This is true they may constantly feel cold however their bodies may not be as cold as they are interpreting it to be. So in fact people at this age will cover up with warm clothes or even turn on the heat during hot days because they feel cold, this will add to their overheating that they do not realize they are experiencing. Another reason that relates to this over 65 age group and the children under four is that both these age groups have a tendency to rely on others for care. Infants cannot hydrate themselves and older people sometimes need this same kind of assistance as they get older. Infants rely on adults around them to keep them safe. Because of their inability to speak and be understood all the time it is much easier for them to suffer from heat fatalities as well. It is important that people caring for infants can see signs and symptoms in infants that relay the message of being overheated, such as constant crying, no tears when crying, or absence or decreasing in wet diapers. Also as we spoke of before the generation of heat comes from energy and in infants they are releasing much more energy from growing and just the response systems of their organs. They tend to already have a higher BMR than middle age or elderly having a higher BMR leaves a smaller range to overheat. In addition the patients that are also at an increased risk on certain medications happen to be patients that have medically conditions that can also exacerbate heat issues. Generally any sensing that may be blocked will increase risk for heat exhaustion because without sensing our bodies ability to try and regulate through homeostasis will be blocked as well. There is essentially no message being sent to our brains that we need to hydrate or cool down.
The thermal ranges are greatly influenced through circulation and fluid in the body. In elderly people they have poor circulation and tend to have a lower temperature of the fluid moving within their bodies because of this poor circulation. Their BMR is less of that of a child so they are less heat creating and require less energy. Children because of growing factors require a lot more energy increasing their BMR. This means that are higher heat producing since heat is related to the release of energy. If they are constantly releasing energy and creating heat they would be a higher risk because the threshold of their temperatures has less room for error.
Heat can be produced through shivering or shaking and this can cause the body to become hyper thermic. Therefore the attempt to keep the body mildly hypothermic in order to decrease BMR is not being accomplished. When cooling the body healthcare facilities try to avoid shivering, because their purpose is to cool down and not have the body release even more heat. In healthcare facilities there is an attempt to immediately to cool down the body and supply it with fluids, that is has long since lost through the hyper thermic process. First you give fluids, these IV fluids are generally chilled at a less than room temperature setting in order to assist with cooling down. They also make sure to remove any excess clothing that can cause heat and sources surrounding the patient that may add heat through radiation or convection. Continuous fanning is used. Lavage can be used through pumping/irrigation of chilled fluids after an NG tube may be inserted. This is generally used for the patients that are so severely hyper thermic they may not be conscious enough to safely swallow.

Works Cited

"Info for Specific Groups." Information for Specific Groups|Extreme Heat. CDC, n.d. Web. 08 Feb. 2014.
Marieb, Elaine Nicpon, and Katja Hoehn. Anatomy & Physiology. San Francisco, CA: Pearson/Benjamin Cummings, 2008. Print.
Beard, Robin M., and Michael W. Day. "Fever And Hyperthermia." Nursing 38.6 (2008): 28-31. Print.
Li, Z. and Srivast.ava, P. 2004. Heat-Shock Proteins. Current Protocols in Immunology, 58:A.1T.1–A.1T.6.

Cited: "Info for Specific Groups." Information for Specific Groups|Extreme Heat. CDC, n.d. Web. 08 Feb. 2014. Marieb, Elaine Nicpon, and Katja Hoehn. Anatomy & Physiology. San Francisco, CA: Pearson/Benjamin Cummings, 2008. Print. Beard, Robin M., and Michael W. Day. "Fever And Hyperthermia." Nursing 38.6 (2008): 28-31. Print. Li, Z. and Srivast.ava, P. 2004. Heat-Shock Proteins. Current Protocols in Immunology, 58:A.1T.1–A.1T.6.