Heatstroke

“ Numerous as the constitutional causes of heat-strokes are, all Indian experience combines to show that drunkenness is the chief." The tropical practitioner will do well to bear this remark in mind; it applies not only to heat- exhaustion, but also to all forms of disease grouped under the term "heat-stroke." Heat-exhaustion, then, is one form of what, when the subject of it happens at the time to be exposed to the sun, is called "sun-stroke," or when the patient happens to be at the time under cover, is called " heat-stroke." ”

“ These experiments have often been alluded to as "baking animals alive." You will note that the heat was no greater than that to which laborers are frequently exposed in our hot summer-days, when working in the sun or in many industrial works. His experiments showed that the effects of sunstroke—or, as he happily termed it, Thermic or heat fever, a scientific name now widely adopted—were solely due to the heat, death following from coagulation of the muscular structure of the heart, or by its effects on the brain. ”

“ No peril need attend a change from a hot to a cold temperature if the power to evolve heat inherent in the system be entire and active and persistent, not lessened by any of those circumstances which have the effect of weakening it, such as local disease, and fatigue. Cold is dangerous, not especially when the body is hot, but when it is cooling after being heated. At such times taking a large draught of cold water, or cooling the body suddenly some other way might cause death immediately; if not, an inflammation of some internal part of the body might arise. ”

“ When our body is bathed in perspiration the fuller condition of the skin occasions an increased transfer of heat from the dilated blood-vessels to the surrounding air by conduction, but generally also by evaporation.
In southern climes, at the hottest and moist time of the year, when the body cannot lose much heat by radiation toward colder objects, when the temperature of the air approaches and even surpasses at times that of our blood, the European often feels the heat to suffocation, and besides the use of the bath he has no other practical remedy than the fan and the shade. ”

“ Indeed, the most effective mechanisms of heat loss involve evaporation of water from the surface of the skin or respiratory pathways (e.g., by sweating, salivation, or polypnea) , which strains the body's precious water resources, whereas heat production (nonshivering or shivering thermogenesis) depletes the body's energy stores. In contrast to autonomic thermoregulation, behavior places no demands on the body's water or energy resources; furthermore, behavioral thermoregulation can compensate for much greater thermal loads. ”

“ Sunstroke occurs in those who work under the direct rays of the sun, when the air is hot, still, and humid.
Heat-stroke or thermic fever affects those working in places which are excessively hot and confined, as in glass-works, foundries, stoke-holds, boiler-houses, sugar-refineries, paper-mills, &c. ”

“ It is very fortunate for us, that our Spring showers are not of ether; for then, instead of thawing, our land would freeze the harder! The heat of the blood is about 98°; yet man can endure a heat of many degrees more, and even labor under a Summer sun, which would raise the thermometer to 130°, without the temperature of his blood being materially affected, and it is because of perspiration, which absorbs the surplus heat, or, in other words, creates cold. ”

“ The mere application of a chill temperature to the skin is not alone, however, enough to give a cold. This result chiefly comes when the application has been made while the body is in a weakened or exhausted state, and therefore has not the power to resist and overcome the internal disturbance of the even blood-flow. Colds are nearly always caught in consequence of a sudden exposure of the body to a chill, either when it is in a state of exhaustion and fatigue from sustained exertion, or when it has been for some time previously over-heated. ”

“ Why, when we say that a little girl was out in the sun, and burned her face and neck, we do not mean that her face and neck were consumed, or that they felt a painful sensation,—but that the skin was reddened by the sun’s heat. So, when we say that the grass was all burned up in the drought, we mean that it was dried and withered. Thus burned and burning are used to denote a great variety of effects produced by heat, which effects are very different from each other in their nature. ”

“ Recovery is often incomplete, resulting in permanent impairment of health, and generally in intolerance of heat and of exposure to the sun. These morbid conditions being due to heat alone, are liable to occur whenever there is exposure to a high temperature, whether solar or artificial. Soldiers marching or fighting, when oppressed by weight of clothing or accoutrements, are apt to suffer either from simple heat-exhaustion or from that form of insolation which results from direct action of a powerful sun on the head and spine. ”

“ A person in a condition of fever, suffering from intense heat arising from a diseased state of the blood, could not be said to be absorbing heat. Nor could such a description apply to a person who, by a very rapid walk, has raised the temperature of his body considerably above its natural state, by the internal combustion which has already been described. A person feeling hot in bed, from excessive clothes, feels hot from the development of heat internally, which is not conducted away with sufficient rapidity to maintain the natural temperature of the body. ”

“ Go to bed, place hot bricks to the feet, take nothing but a little gruel or beef tea, and drink moderately of warm, cream-of-tartar water. If you do not feel better the next morning, call a physician. If that be impossible, take a dose of castor oil or Epsom salts.
SUNSTROKE is a sudden prostration caused by intense heat. The same effect is produced by the burning rays of the sun and the fierce fire of a furnace. When a person falls under such circumstance, place your hand on his chest. If the skin be cool and moist, it is not a sunstroke ”

“ Death from extreme heat usually occurs in the form of burning and scalding, attended with destruction of a large portion of the cutaneous structures. Here the cause of death is obvious. The human body is capable of exposure to very hot air—as is seen in Turkish baths—for a considerable period with impunity. Sunstroke is a cerebral affection brought on by too great exposure to a hot atmosphere, especially whilst undergoing fatigue. ”

“ The reason of this is, that we cannot feel warm till we have been cold, and vice versâ."
"Our bodies," resumed Fritz, "however much the thermometer descends, never mark less than thirty-five degrees above zero. In winter the skin shrinks, and becomes a bad conductor of heat from without; but, at the same time, does not allow so much gas and vapor to escape from within. In summer, on the contrary, the skin dilates and allows perspiration to form, a process that consumes a considerable amount of latent heat. ”

“ The cause of heat-stroke with its high fever is unknown, but probably it is due to some effect on the heat center in the brain. Heat prostration is also due to prolonged exposure to heat, but is generally accompanied by a subnormal temperature. The effect of cold, as in freezing, is to diminish all the metabolic activities of the body. The temperature can be artificially regulated more or less by variations of food, varying amounts of exercise, by drugs, etc. ”

“ Evidently in the direct action of heat upon the human body we have the most powerful agency in the production of our great summer mortality. While sunstroke represents the maximum direct effect of solar heat upon the human subject, the large increase of deaths from wasting chronic diseases and diarrhœal affections, of children under one year of age and persons upward of seventy years of age, shows the terrible effects of the prevailing intense heat of summer upon all who are debilitated by disease or age and thereby have their "heat-regulating power" diminished. ”

“ If one pint pot of boiling water be placed in out-of-door air that is cold as freezing water, and another be placed at the same time in a room where the air has the warmth of a mild summer day, the former will be deprived of all its excess of heat much sooner than the latter.
Warm bodies lose their excess of heat in two ways. They shoot it off into surrounding space. This is what learned men call “raying” or “radiating” it away. The sun, you know, shoots or rays its heat off to the earth, and so does the fire to your body when you stand before it. ”

“ The danger is, in the first instance, the local perturbation in our heat-economy, which has partly local consequences, but also and chiefly disorders the nerves, acting on the calibre of our blood-vessels, our vaso-motor nerves, which have to regulate the outflow of our heat. When we are in the open, and the air is in more motion than the air of a draught, we speak of wind, etc., but seldom of draught, because the whole air-current flows equally all round us, just as in a well-ventilated room, only with greater velocity. ”

“ After some years of investigation he advanced the theory that every great atmospheric disturbance begins with the uprising of air which has been rarefied by heat. The rising mass dilates, and, as its temperature falls, precipitates vapor in the form of clouds. Owing to the liberation of the latent heat, the dilation continues with the rising till the moisture of the air forming the upward current is practically exhausted. The heavier air flows in beneath, and, finding a diminished pressure above it, rushes upward with constantly increasing violence. ”

“ SYNONYMS.—Coup de soleil, Sunstroke, Heat apoplexy, Heat asphyxia, Heat fever, Sun fever, Thermohæmia, Erethismus tropicus, Insolation.
The immediate cause of thermic fever is always exposure to excessive heat in some form. As the body can cool itself much more readily in a dry than in a moist atmosphere, it is able to resist the influence of a dry, overheated air much better than when there is also moisture. ”

“ But taking cold in the second sense of the word, “the sensation produced by the escape of heat” from the body; “chilliness or chillness”—see Webster’s second definition—every one knows by actual experience that this depends to a considerable degree upon the dryness and stillness of the atmosphere and the state of the body. Exposed to a high wind in humid atmosphere not more than 5 or 6 degrees below zero, a person may freeze to death, when he would endure 35 or 40 degrees below zero in a dry, still air without serious suffering. Such air is classed among the poorest of all heat conductors ”

“ Though generally happening from exposure to the sun's rays, yet precisely similar effects may be and are produced from any undue exposure to great and exhaustive heat, such as workmen are exposed to in foundries, gas factories, bakeries, and other similar employments. Its first symptom is pain in the head and dizziness, quickly followed by loss of consciousness, and resulting in complete prostration: sometimes, however, the attack is sudden, as in apoplexy. The head is generally burning hot, the face, dark and swollen, the breathing labored and snoring, and the feet and hands cold. ”

“ While admitting that there may be cases where the effects of certain rays of the sun are responsible for clinical manifestations varying from death of striking suddenness to vague complaints of irritability, headache and defective memory, yet the generally accepted views are that high temperature, high relative humidity and lack of evaporation from the skin, whether from excessive humidity or from lack of circulation of the surrounding air, can and do produce at one time heat stroke and at another heat prostration. ”

“ Every thing that has the effect of weakening the system and so diminishing the power of evolving heat, favors the morbific effect of cold, and is a predisposing cause of disease. The most common of these debilitating circumstances are fasting, evacuations, fatigue, a last night’s debauch, excess in venery, long watching, much study, and rest or inaction immediately after it, or after great exercise.
The faculty of evolving heat is weak in old persons and in the newly born, and these are often the victims of the power of cold. ”

“ Too great an elevation or too great a depression of temperature may destroy the "heat-regulating power," and disease or death will be the consequence. Or this "heat-regulating power" may be weakened or destroyed by causes generated within the body, or received from without, and the heat-producing agencies are then under influences which may prove to be powerfully destructive forces. ”

“ Sugg’s Gas Fires.—During a greater part of the year in this country, the variations in the temperature are so great and sudden, that those persons who have weak throats, or are subject to bronchitis—especially children who have a tendency to croup—find the cold, air of the early mornings a source of great discomfort and even danger. Although by the use of coal fires, with constant attention, the temperature of a bedroom or sick room can be maintained as required during the day, yet at night it is next to impossible to do so. ”

“ The attendant conditions have much influence in determining an attack, thus it is generally held that heat with excess of moisture is the most injurious, yet in Cincinnati, statistics showed a greater number of cases in man when the air was dry. The suppression of perspiration and the arrest of cooling by evaporation in the latter case would tend to a rapid increase of the body temperature, and the condition would be aggravated by the electric tension usually present with the dry air. ”

“ Above this the smoke-wreaths will remain merely waving about, with slight movements due to the small inequalities of temperature caused by the fraction of heat radiated into the room from the front of the fire. These movements are chiefly developed near the door and windows, where the above-mentioned cascades are falling, and against the walls and furniture, where feeble convection currents are rising, due to the radiant heat absorbed by their surfaces. The stagnation is the most complete about the middle of the room, where there is the greatest bulk of vacant airspace. ”