Final answer:
Hypothermia describes an extremely low body temperature that can be life-threatening. Controlled hypothermia is a medical technique used to protect organs by slowing metabolism, which is particularly useful during heart surgery and after cardiac arrest to reduce heart damage.
Step-by-step explanation:
Hypothermia is the clinical term for an abnormally low body temperature, which is a dangerous decrease in core body temperature below 34.4 degrees Celsius (94 degrees Fahrenheit). It is a condition that can arise when the body loses heat faster than it can produce it, leading to a drop in heart rate and strength of heart contractions. Severe hypothermia can result in red blood cells losing their ability to give up oxygen, potentially leading to confusion, lethargy, eventual loss of consciousness, and even death.
In medical situations, controlled hypothermia is used beneficially during certain procedures, such as open-heart surgery, to reduce the metabolic rate of the brain, heart, and other organs, thereby reducing the risk of damage to them. During this process, to avoid the body's natural shivering response which generates heat, patients are given medications and their core temperature is reduced. Lowering the body temperature slows the patient's metabolic rate, lessening the heart's workload and organ demand for blood.
Additionally, emergency physicians may use controlled hypothermia to help patients who have suffered a cardiac arrest. By inducing a coma and lowering body temperature to around 91 degrees Fahrenheit, they can reduce cardiac damage by minimizing the body's metabolic demands.