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February 10, 2012

Heat-Related Illness Glossary of Terms

The following are health and medical definitions of terms that appear in the Heat-Related Illness article.

Abdomen: The belly, that part of the body that contains all of the structures between the chest and the pelvis. The abdomen is separated anatomically from the chest by the diaphragm, the powerful muscle spanning the body cavity below the lungs.
See the entire definition of Abdomen

Airway: The path air follows to get into and out of the lungs. The mouth and nose are the normal entry and exit ports. Entering air then passes through the back of the throat (pharynx), continues through the voice box (larynx), down the trachea, and finally out the branching tubes known as bronchi.

Arms: An appendage in anatomy and in clinical trials. See: Arm.

Blood pressure: The blood pressure is the pressure of the blood within the arteries. It is produced primarily by the contraction of the heart muscle. It's measurement is recorded by two numbers. The first (systolic pressure) is measured after the heart contracts and is highest. The second (diastolic pressure) is measured before the heart contracts and lowest. A blood pressure cuff is used to measure the pressure. Elevation of blood pressure is called "hypertension".

Brain: That part of the central nervous system that is located within the cranium (skull). The brain functions as the primary receiver, organizer and distributor of information for the body. It has two (right and left) halves called "hemispheres."

Breathing: The process of respiration, during which air is inhaled into the lungs through the mouth or nose due to muscle contraction, and then exhaled due to muscle relaxation.

Caffeine: A stimulant found naturally in coffee beans, tea leaves, cocoa beans (chocolate) and kola nuts (cola) and added to soft drinks, foods, and medicines. A cup of coffee has 100-250 milligrams of caffeine. Black tea brewed for 4 minutes has 40-100 milligrams. Green tea has one-third as much caffeine as black tea.
See the entire definition of Caffeine

Chest: The area of the body located between the neck and the abdomen. The chest contains the lungs, the heart and part of the aorta. The walls of the chest are supported by the dorsal vertebrae, the ribs, and the sternum.
See the entire definition of Chest

Chest pain: There are many causes of chest pain. One is angina which results from inadequate oxygen supply to the heart muscle. Angina can be caused by coronary artery disease or spasm of the coronary arteries. Chest pain can also be due to a heart attack (coronary occlusion) and other important diseases such as, for example, dissection of the aorta and a pulmonary embolism. Do not try to ignore chest pain and "work (or play) though it." Chest pain is a warning to seek medical attention.

Chronic: This important term in medicine comes from the Greek chronos, time and means lasting a long time.
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Circulation: The movement of fluid in a regular or circuitous course. Although the noun "circulation" does not necessarily refer to the circulation of the blood, for all practical purposes today it does. Heart failure is an example of a problem with the circulation.

Cluster: In epidemiology, an aggregation of cases of a disease or another health-related condition, such as a cancer or birth defect, closely grouped in time and place. The number of cases in the cluster may or may not exceed the expected number. This is determined by cluster analysis, a set of statistical methods used to analyze clusters.

Coma: A state of deep unarousable unconsciousness.
See the entire definition of Coma

Dehydration: Excessive loss of body water. Diseases of the gastrointestinal tract that cause vomiting or diarrhea may, for example, lead to dehydration. There are a number of other causes of dehydration including heat exposure, prolonged vigorous exercise (e.g., in a marathon), kidney disease, and medications (diuretics).
See the entire definition of Dehydration

Depression: An illness that involves the body, mood, and thoughts, that affects the way a person eats and sleeps, the way one feels about oneself, and the way one thinks about things. A depressive disorder is not the same as a passing blue mood. It is not a sign of personal weakness or a condition that can be wished away. People with a depressive disease cannot merely "pull themselves together" and get better. Without treatment, symptoms can last for weeks, months, or years. Appropriate treatment, however, can help most people with depression.
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Diabetes: Refers to diabetes mellitus or, less often, to diabetes insipidus. Diabetes mellitus and diabetes insipidus share the name "diabetes" because they are both conditions characterized by excessive urination (polyuria).
See the entire definition of Diabetes

Dizziness: Painless head discomfort with many possible causes including disturbances of vision, the brain, balance (vestibular) system of the inner ear, and gastrointestinal system. Dizziness is a medically indistinct term which laypersons use to describe a variety of conditions ranging from lightheadedness, unsteadiness to vertigo.
See the entire definition of Dizziness

Elbow: The juncture of the long bones in the middle portion of the arm. The bone of the upper arm (humerus) meets both the ulna (the inner bone of the forearm) and radius (the outer bone of the forearm) to form a hinge joint at the elbow. The radius and ulna also meet one another in the elbow to permit a small amount of rotation of the forearm. The elbow therefore functions to move the arm like a hinge (forward and backward) and in rotation (outward and inward). The biceps muscle is the major muscle that flexes the elbow hinge, and the triceps muscle is the major muscle that extends it. The primary stability of the elbow is provided by the ulnar collateral ligament, located on the medial (inner) side of the elbow. The outer bony prominence of the elbow is the lateral epicondyle, a part of the humerus bone. Tendons attached to this area can be injured, causing inflammation or tendonitis (lateral epicondylitis, or tennis elbow). The inner portion of the elbow is a bony prominence called the medial epicondyle of the humerus. Additional tendons from muscles attach here and can be injured, likewise causing inflammation or tendonitis (medial epicondylitis, or golfer's elbow). See also: Elbow bursitis; Elbow pain; Nursemaid's elbow.

Electrolyte: An electrolyte is a substance that will dissociate into ions in solution and acquire the capacity to conduct electricity. The electrolytes include sodium, potassium, chloride, calcium and phosphate. Informally, called lytes. (The clue to the word electrolyte is in the lyte which comes from the Greek lytos meaning that may be dissolved.)

Fatigue: A condition characterized by a lessened capacity for work and reduced efficiency of accomplishment, usually accompanied by a feeling of weariness and tiredness. Fatigue can be acute and come on suddenly or chronic and persist.
See the entire definition of Fatigue

Fever: Although a fever technically is any body temperature above the normal of 98.6 degrees F. (37 degrees C.), in practice a person is usually not considered to have a significant fever until the temperature is above 100.4 degrees F (38 degrees C.).
See the entire definition of Fever

Groin: In anatomy, the area where the upper thigh meets the trunk. More precisely, the fold or depression marking the juncture of the lower abdomen and the inner part of the thigh.
See the entire definition of Groin

Headache: A pain in the head with the pain being above the eyes or the ears, behind the head (occipital), or in the back of the upper neck. Headache, like chest pain or back ache, has many causes.
See the entire definition of Headache

Heart: The muscle that pumps blood received from veins into arteries throughout the body. It is positioned in the chest behind the sternum (breastbone; in front of the trachea, esophagus, and aorta; and above the diaphragm muscle that separates the chest and abdominal cavities. The normal heart is about the size of a closed fist, and weighs about 10.5 ounces. It is cone-shaped, with the point of the cone pointing down to the left. Two-thirds of the heart lies in the left side of the chest with the balance in the right chest.
See the entire definition of Heart

Heart disease: Any disorder that affects the heart. Sometimes the term "heart disease" is used narrowly and incorrectly as a synonym for coronary artery disease. Heart disease is synonymous with cardiac disease but not with cardiovascular disease which is any disease of the heart or blood vessels. Among the many types of heart disease, see, for example: Angina; Arrhythmia; Congenital heart disease; Coronary artery disease (CAD); Dilated cardiomyopathy; Heart attack (myocardial infarction); Heart failure; Hypertrophic cardiomyopathy; Mitral regurgitation; Mitral valve prolapse; and Pulmonary stenosis.

Heart rate: The number of heart beats per unit time, usually per minute. The heart rate is based on the number of contractions of the ventricles (the lower chambers of the heart). The heart rate may be too fast (tachycardia) or too slow (bradycardia). The pulse is bulge of an artery from the wave of blood coursing through the blood vessel as a result of the heart beat. The pulse is often taken at the wrist to estimate the heart rate.

Heat cramps: Painful muscle spasms in the abdomen, arms, or legs following strenuous activity. The skin is usually moist and cool and the pulse is normal or slightly raised. Body temperature is mostly normal. Heat cramps often are caused by a lack of salt in the body, but salt replacement should not be considered without advice from a physician. Heat cramps usually affect people who sweat a lot during strenuous activity. The sweating depletes the body's salt and moisture. The low salt level in the muscles causes painful cramps. Heat cramps may also be a symptom of heat exhaustion.
See the entire definition of Heat cramps

Heat exhaustion: A warning that the body is getting too hot. The person may be thirsty, giddy, weak, uncoordinated, nauseous, and sweating profusely. The body temperature is usually normal and the pulse is normal or raised. The skin is cold and clammy. Although heat exhaustion often is caused by the body's loss of water and salt, salt supplements should only be taken with advice from a doctor.
See the entire definition of Heat exhaustion

Heat stroke: A core body temperature that rises above 104 F (40 C) accompanied by hot, dry skin and central nervous system abnormalities such as delirium, convulsions, or coma. Heat stroke that results from exposure to a high environmental temperature is called nonexertional heat stroke. Heat stroke that results from strenuous exercise is called exertional heat stroke. Irrespective of type, heat stroke can be LIFE-THREATENING! Immediate medical attention is essential when problems first begin. Symptoms may include confusion, combativeness, bizarre behavior, faintness, staggering, strong rapid pulse, dry flushed skin, lack of sweating, possible delirium or coma.
See the entire definition of Heat stroke

Heat syncope: Sudden dizziness, feeling faint ans sometimes fainting experienced after exercising in the heat. The skin appears pale and sweaty but is generally moist and cool. The pulse may be weakened, and the heart rate is usually rapid. Body temperature is normal.

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Heat-related illness: A person with symptoms including headache, nausea, and fatigue after exposure to heat probably has some measure of a heat-related illness. It is important to recognize the difference between the very serious condition known as heat stroke and other heat-related illnesses. Persons experiencing any of these symptoms should consult a doctor.
See the entire definition of Heat-related illness

High blood pressure: Also known as hypertension, high blood pressure is, by definition, a repeatedly elevated blood pressure exceeding 140 over 90 mmHg -- a systolic pressure above 140 with a diastolic pressure above 90.
See the entire definition of High blood pressure

Hyperthermia: Overheating of the body. This may be due to extreme weather conditions. Unrelieved hyperthermia can lead to collapse and death, particularly in the elderly. Prevention via air conditioning, ventilation, and drinking extra water is the key for vulnerable persons. In emergency cases, injections of saline solution and rapid cooling of the body may be needed. Also known as heatstroke or heat prostration.

Injury: Harm or hurt. The term "injury" may be applied in medicine to damage inflicted upon oneself as in a hamstring injury or by an external agent on as in a cold injury. The injury may be accidental or deliberate, as with a needlestick injury. The term "injury" may be synonymous (depending on the context) with a wound or with trauma.

Insomnia: The perception or complaint of inadequate or poor-quality sleep because of one or more of the following: difficulty falling asleep; waking up frequently during the night with difficulty returning to sleep; waking up too early in the morning; or unrefreshing sleep. Insomnia is not defined by the number of hours of sleep a person gets or how long it takes to fall asleep. Individuals vary normally in their need for, and their satisfaction with, sleep. Insomnia may cause problems during the day, such as tiredness, a lack of energy, difficulty concentrating, and irritability.
See the entire definition of Insomnia

Lightheadedness: A feeling you are "going to faint." Lightheadedness is medically distinct from dizziness, unsteadiness, and vertigo. See: Dizziness, Unsteadiness, and Vertigo.

Mouth: 1. The upper opening of the digestive tract, beginning with the lips and containing the teeth, gums, and tongue. Foodstuffs are broken down mechanically in the mouth by chewing and saliva is added as a lubricant. Saliva contains amylase, an enzyme that digests starch. 2. Any opening or aperture in the body. The mouth in both senses of the word is also called the os, the Latin word for an opening, or mouth. The o in os is pronounced as in hope. The genitive form of os is oris from which comes the word oral.

Muscle: Muscle is the tissue of the body which primarily functions as a source of power. There are three types of muscle in the body. Muscle which is responsible for moving extremities and external areas of the body is called "skeletal muscle." Heart muscle is called "cardiac muscle." Muscle that is in the walls of arteries and bowel is called "smooth muscle."

Nausea: Nausea, is the urge to vomit. It can be brought by many causes including, systemic illnesses, such as influenza, medications, pain, and inner ear disease. When nausea and/or vomiting are persistent, or when they are accompanied by other severe symptoms such as abdominal pain, jaundice, fever, or bleeding, a physician should be consulted.

Neck: The part of the body joining the head to the shoulders. Also, any narrow or constricted part of a bone or organ that joins its parts as, for example, the neck of the femur bone.

Obese: Well above ones normal weight. A person has traditionally been considered to be obese if they are more than 20 percent over their ideal weight. That ideal weight must take into account the person's height, age, sex, and build.
See the entire definition of Obese

Obesity: The state of being well above one's normal weight.
See the entire definition of Obesity

Overweight: The term "overweight" is used in two different ways. In one sense it is a way of saying imprecisely that someone is heavy. The other sense of "overweight" is more precise and designates a state between normal weight and obesity.
See the entire definition of Overweight

Pain: An unpleasant sensation that can range from mild, localized discomfort to agony. Pain has both physical and emotional components. The physical part of pain results from nerve stimulation. Pain may be contained to a discrete area, as in an injury, or it can be more diffuse, as in disorders like fibromyalgia. Pain is mediated by specific nerve fibers that carry the pain impulses to the brain where their conscious appreciation may be modified by many factors.
See the entire definition of Pain

Pimples: Small papules or pustules. See: Pimple.

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Poor circulation: An inadequacy of blood flow. Inadequate blood flow to a particular area of the body can result in too little oxygen being delivered to that area, a condition known as hypoxia. The term poor circulation may be used to refer to peripheral vascular disease (or peripheral arterial disease), a condition that develops when the arteries that supply blood to the internal organs, arms, and legs become completely or partially blocked as a result of atherosclerosis.

Pound: A measure of weight equal to 16 ounces or, metrically, 453.6 grams. The word "pound" goes back to the Latin "pondo" which meant a "weight" (but one of only 12 ounces). The abbreviation for pound-just to confuse non-pound people-is lb. which stands for "libra" (Latin for pound).

Pulse: The rhythmic contraction and expansion of an artery due to the surge of blood from the beat of the heart. The pulse is most often measured by feeling the arteries of the wrist. There is also a pulse, although far weaker, in veins.

Rash: Breaking out (eruption) of the skin. Medically, a rash is referred to as an exanthem.

Rehydration: The process of restoring lost water to the body tissues and fluids. Prompt rehydration is imperative whenever dehydration occurs, from diarrhea, exposure, lack of drinking water, or medication use. Rehydration can be by the oral route or by the intravenous administration of fluids.

Seizure: Uncontrolled electrical activity in the brain, which may produce a physical convulsion, minor physical signs, thought disturbances, or a combination of symptoms.
See the entire definition of Seizure

Sodium: The major positive ion (cation) in fluid outside of cells. The chemical notation for sodium is Na+. When combined with chloride, the resulting substance is table salt.
See the entire definition of Sodium

SPF (sun protection factor): A number on a scale for rating the degree of protection provided by sunscreens. SPF stands for Sun Protection Factor.
See the entire definition of SPF

Stomach: 1. The sac-shaped digestive organ that is located in the upper abdomen, under the ribs. The upper part of the stomach connects to the esophagus, and the lower part leads into the small intestine.
See the entire definition of Stomach

Stomach cramps: A nonmedical term most often used to describe pain in the mid- or upper abdominal area. Abdominal pain (pain in the belly) can come from conditions affecting a variety of organs and does not necessarily arise from the stomach even though an individual may perceive that pain is originating in the stomach. Various organs can be the source of pain in the upper abdomen, including the small intestine, colon, liver, gallbladder, and pancreas.

Stress: Forces from the outside world impinging on the individual. Stress is a normal part of life that can help us learn and grow. Conversely, stress can cause us significant problems.
See the entire definition of Stress

Stroke: The sudden death of some brain cells due to a lack of oxygen when the blood flow to the brain is impaired by blockage or rupture of an artery to the brain. A stroke is also called a cerebrovascular accident or, for short, a CVA.
See the entire definition of Stroke

Sunburn: Sunburn is an inflammation of the skin that develops in response to exposure to ultraviolet (UV) radiation from the sun or from tanning beds and booths that emit UV radiation. Sunburn is manifested by reddened, painful skin that may develop blisters.
See the entire definition of Sunburn

Sunscreen: A substance that blocks the effect of the sun's harmful rays. Using lotions that contain sunscreens can reduce the risk of skin cancer, including melanoma.

Sweat: A colorless transparent acidic fluid with a distinctive odor secreted by the small tubular sudoriferous (sweat) glands situated within the skin and under it in the subcutaneous tissue. The sweat glands discharge their fluid through tiny openings in the surface of the skin.
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Sweating: The act of secreting fluid from the skin by the sweat (sudoriferous) glands. These are small tubular glands situated within and under the skin (in the subcutaneous tissue). They discharge by tiny openings in the surface of the skin.
See the entire definition of Sweating

Symptom: Any subjective evidence of disease. Anxiety, lower back pain, and fatigue are all symptoms. They are sensations only the patient can perceive. In contrast, a sign is objective evidence of disease. A bloody nose is a sign. It is evident to the patient, doctor, nurse and other observers.

Syncope: Partial or complete loss of consciousness with interruption of awareness of oneself and ones surroundings. When the loss of consciousness is temporary and there is spontaneous recovery, it is referred to as syncope or, in nonmedical quarters, fainting. Syncope accounts for one in every 30 visits to an emergency room. It is pronounced sin-ko-pea.
See the entire definition of Syncope

Thermostat: A device that monitors temperature and automatically maintains it at certain levels. In a human, a tiny part of the brain called the hypothalamus, located behind the eyes, serves as the thermostat. It can warm the body by causing it to shiver and cool the body by causing it to perspire. The hypothalamus also regulates hunger, thirst, sex drive and other body activities.
See the entire definition of Thermostat

Twitch: an involuntary contraction of a group of muscles, also known as a fasciculation.

Vital: Necessary to maintain life. Breathing is a vital function.

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Suggested Reading on Heat-Related Illness by Our Doctors

  • Related Diseases & Conditions

    • Rash
      • The word "rash" means an outbreak of red bumps on the body. The way people use this term, "a rash" can refer to many different skin conditions. The most common of these are scaly patches of skin and red, itchy bumps or patches all over the place.
    • Dehydration
      • Dehydration is the excessive loss of body water. There are a number of causes of dehydration including heat exposure, prolonged vigorous exercise, and some diseases of the gastrointestinal tract. The best way to treat dehydration is to prevent it from occurring.
    • Muscle Spasms
      • Muscle spasms are involuntary muscle contractions that come on suddenly and are usually quite painful. Dehydration, doing strenuous exercise in a hot environment, prolonged muscle use, and certain diseases of the nervous system may cause muscle spasms. Symptoms and signs of a muscle spasm include an acute onset of pain and a possible bulge seen or felt beneath the skin where the muscle is located. Gently stretching the muscle usually resolves a muscle spasm.
    • Heat Rash
      • Heat rash is a skin irritation caused by excessive sweating. It can occur at any age and it appears as a rash that itches or feels prickly, and looks like a red cluster of pimples or small blisters. Pictures of heat rash are included.
    • Rhabdomyolysis
      • Rhabdomyolysis is a rapid deterioration and destruction of skeletal muscle. Some of the causes of rhabdomyolysis include severe burns, muscle trauma, coma, seizures, electrolyte imbalance, medications (statins), viruses, bacteria. Treatment of rhabdomyolysis depends on the cause.
    • Heat Stroke
      • Heat stroke (heatstroke or sun stroke) is a form of hyperthermia. Heat stroke is a true medical emergency that can be fatal if not promptly and properly treated. Symptoms of heat stroke include: high body temperature, absence of sweating, with hot red or flushed dry skin, rapid pulse, difficulty breathing, strange behavior, hallucinations, confusion, agitation, disorientation, seizure, and coma. A victim of heat stroke must receive immediate treatment to avoid permanent organ damage.
    • Heat Exhaustion
      • Heat exhaustion is a milder form of heat-related illness that can develop after several days of exposure to high temperatures and inadequate or unbalanced replacement fluids. Warning signs of heat exhaustion include heavy sweating, paleness, muscle cramps, tiredness, weakness, dizziness, headache, nausea or vomiting, and fainting.
    • Shock (Medical)
      • Medical shock is a life-threatening medical condition. There are several types of medical shock, septic shock, anaphylactic shock, cardiogenic shock, hypovolemic shock, and neurogenic shock. Causes of shock include heart attack, heart failure, heavy bleeding (internal and external), infection, anaphylaxis, spinal cord injury, severe burns, chronic vomiting or diarrhea. Low blood pressure is the key sign of sock. Treatment is dependant upon the type of shock.
    • Sun-Sensitive Drugs (Photosensitivity to Drugs)
      • Sun sensitivity (photosensitivity) is an inflammation of the skin induced by the combination of medications or substances and sunlight. The affect on the skin is redness, which looks similar to a sunburn. Generally, these reactions are either phototoxic or photoallergic. Phototoxic drugs are more common than photoallergic drugs. Symptoms of phototoxic reactions are a burning and stinging sensation and then redness. Symptoms of photoallergic reactions are itching, redness, swelling, blisters of the affected area. Treatment generally is discontinuation of the medication and topical application of creams.
    • Fitness
      • Regular physical activity can reduce the risk of disease. Regular exercise can also reduce the symptoms of stress and anxiety. There are fitness programs that fit any age or lifestyle.
    • Heat Cramps
      • Heat cramps usually affect people who sweat a lot during strenuous activity or work in a hot humid environment. Symptoms of heat cramps are muscle pains or spasms, usually in the abdomen, arms or legs that occur in association with strenuous activity. Heat cramps is part of a group of heat-related illnesses.
    • First Aid
      • First aid is a complicated subject and it is situation-specific. First aid is the help and medical assistance that someone gives, not only to an injured person, but to a person who is sick. Preparedness is a key element of first aid, like having basic medical emergency kits in your home, car, boat, or RV. Cuts, puncture wounds, sprains, strains, nosebleeds are one type of injury that may require first aid; heart attacks, strokes, seizures, and heat stroke are examples of more critical first aid emergencies.
    • Sudden Infant Death Syndrome (SIDS)
      • The cause of sudden infant death syndrome (SIDS) is unknown. The risk of SIDS peaks in infants 2-4 months of age. SIDS is more common among male infants, particularly African American and Native American infants, during the winter months. Putting the baby to sleep on his/her back, avoiding fluffy, loose bedding, using a firm mattress, and avoiding co-sleeping may help to prevent SIDS.
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Heat-Related Illness

What are noninfectious, common rashes localized to a particular anatomical area?

Common, noninfectious rashes are listed below. Since these conditions are not caused by infectious organisms, it is reasonable to attempt to treat them with over-the-counter 1% hydrocortisone cream for a week or so prior to seeking medical attention.

Seborrheic dermatitis: Seborrheic dermatitis is the single most common rash affecting adults. It produces a red, scaling eruption that characteristically affects the scalp, forehead, brows, cheeks, and external ears.

Atopic dermatitis: Atopic dermatitis, often called eczema, is a common disorder of childhood which produces red, itchy, weeping rashes on the inner aspects of the elbows and in back of the knees as well as the cheeks, neck, wrists, and ankles. It is commonly found in patients who also have asthma and hay fever.

Contact dermatitis: Contact dermatitis is a r...

Read the Rash article »







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