Text-book of forensic medicine and toxicology

by R. J. M. Buchanan

DEATH FROM EXPOSURE TO HEAT

The results from exposure to excessive heat manifest themselves in various ways. Any condition which may lessen the resistance of the body to external heat predisposes to heat-stroke; such as privation, fatigue, mental emotions, alcohol, over-eating, and especially previous attacks of the disease.

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.

Heat exhaustion and prostration are brought about in a similar manner, but the effects are not the same, and usually transient and less severe.

Sunstroke or heat-stroke may occur in two forms, the asphyxial or apoplectic, and the hyperpyrexial; it is also classified as sthenic or asphyxial, and asthenic or syncopal.

Asphyxial sunstroke or heat apoplexy is probably the least frequent; prodromal symptoms are headache, vertigo, disturbances of vision, dyspnœa, and dry skin. In some cases sudden unconsciousness, with or without convulsions, may occur, and death rapidly follows.

The coma may not be profound; there may be nausea and vomiting of dark material, bounding pulse, stertorous breathing, contracted pupils, and frequent micturition. The body exhales a “mousey odour.” There may be involuntary dejection, with the same pungent odour, and very watery. Delirium is present in some cases. The temperature may be subnormal, or rise to 102° F., occasionally even to 106° F. When fatal, the coma deepens, the pulse becomes rapid and feeble, and there is Cheyne-Stokes respiration.

In Hyperpyrexial cases the symptoms are similar to the asphyxial, but the temperature may reach 110-115° F., and in profound coma death takes place from asphyxia. A subconscious or automatic state, in which the person may go on working, may precede the “stroke.”

In cases which are not so rapid, pneumonia, meningitis, cardiac and respiratory paralysis may occur and prove fatal.

Heat exhaustion may be more gradual in its onset, or come on suddenly. Prodromal dizziness, faintness, nausea, headache, drowsiness, epigastric and lumbar pains may precede the prostration and muscular weakness. Fever supervenes, a rapid pulse, and in severe cases collapse. Consciousness is seldom completely lost, and in favourable cases is quickly regained. When there is marked prostration the heart may fail.

The condition known as heat prostration is a milder form, in which there is little or no fever, and the circulation remains good.

After suffering from an attack of heat-stroke certain sequelæ have been noted. The patients are rendered sensitive to slight elevations of temperature, and, during warm weather, experience chromatopsia, headaches, irritability, irascibility, and even delirium. Epilepsy and insanity may persist during life. Fiske from his investigations concludes that the habits of those working in hot atmospheres, and the degree of temperature, are not nearly so important as the absence of thorough ventilation as causative factors in the disease.

Post-mortem Appearances.—Rigor mortis comes on early, and is pronounced and disappears quickly. Putrefaction is early in onset. The brain and cord, the lungs and spleen and splanchnic area exhibit venous engorgement.

The blood is fluid, and the red corpuscles crenated. Extravasations of blood may be present in the skin, the serous membranes, and cavities, the superior sympathetic ganglia, and the vagi and phrenics. The left ventricle is markedly contracted, the right dilated and filled with blood.

Van Gieson records acute parenchymatous degeneration of the whole of the cerebro-spinal nervous system, with chromatolysis of the cells. Parenchymatous changes may be present in the liver and kidneys.

DEATH BY LIGHTNING AND
ELECTRICITY

LIGHTNING

Death is not always immediate. Sometimes the clothes have been torn off the body with scarcely any personal injury. Metallic articles, especially steel, worn or carried about the person become magnetic and may be fused. The lesions which may be met with after lightning-stroke are varied, and may comprise wounds of almost any description; simple, compound, or comminuted fractures of bones; burns in the form of streaks, patches, lines, or arborescent markings; ecchymoses; singeing of the hair; impressions of metallic articles on the skin. Apart from the lesions noted above, the following symptoms may be present: deafness, blindness, paralysis, loss of memory, delirium, and convulsions. Not infrequently those killed by lightning are found in the same position that they occupied during life. The question may arise as to whether the deceased died by lightning or violence. The presence of a storm at the time when death is stated to have occurred, and other attendant circumstances, will in most cases point to the true cause of death. Metallic articles should be examined with regard to their electric state. Dr. Honiball tenders this caution: “Be not too sure that in every body found dead after a thunderstorm, and where no marks upon it are found, that death was due to lightning-stroke, for it may happen that death was due solely to cardiac syncope owing to sudden and startling fright.”

Post-mortem Appearances.—Apart from the external injuries, when present, post-mortem rigidity comes on early. The head and neck may be purplish in colour, the eyes partially open and suffused, with variable pupils. The internal signs are not characteristic. The membranes and vessels of the brain may be hyperæmic. The blood has been said to be very fluid, but it may be coagulated. The internal organs may be torn, bones may be fractured, and blood-vessels ruptured.