DEATH DUE TO COLD AND HEAT
A. COLD (HYPOTHERMIA)
The normal body temperature is 37 C at which the body performs optimum function. But when this temperature gets lowered, we feel cold and ultimately a person dies due to cold once the degree of coldness crosses the threshold limit.
Effects of cold upon the tissue results from 3 factors:
- Extreme vasoconstriction – causing ischemia, a protective mechanism.
- Intra or extracellular formation of ice crystals.
- Injury of small blood vessels with the formation of clot (agglutinative thrombi) within them
Symptoms
- Local : freezing of skin at -8 to -10 C, resulting into formation of frostbite (either deep and serious or superficial), formation of blister which appears in 3-7 days , or formation of slough
- General : no mild effect from the moderate cold but exposure to severe could continuing for a long time produces deleterious effects. However, artificial hypothermia is used in the operations where the body temperature is lowered.
Treatment
- A rapid thorough re-warming of the patient using warm H2O 40-42 C.
- The affected parts should never be rewarmed by use of exercise.
- A foreign part should never be rubbed before, during or after rewarming.
- Alcohol, tobacco which interfere with peripheral circulation should be avoided.
Postmortem appearance
- External: Red patches of frost-crythems especially on the exposed body parts. Rigor mortis is slow to appear and lasts longer. Prevents decomposition
- Internal: tissue anoxia, clotting of blood in the smaller vessels , blood is dark red in color except in heart
B. HEAT
General effects:
- Heat stroke - sun stroke, heat hyperpyrexia
- Heat cramps – minor cramps
- Heat Exhaustion – heat syncope
Local effects:
- Burns - dry heat injury
- Scald – moist heat injury
The tolerance of heat depends upon 2 factors, they are: -
- Endogenous factors - It includes the internal regulating mechanism and metabolism state of a person. Such as : mental and physical state of a person, personal tolerance, regional climate occupational capacity.
- Exogenous factors – atmospheric temperature, humidity, air environment, clothing and naked situation of the victim.
Effects due to Heat
- Heat stroke: it occurs usually in the tropics due to long exposure under scorching sun.
- Heat cramps: it occurs especially among the workers, due to loss of body fluid and salt, caused by the loss of NaCL in the blood due to excessive sweating
- Heat exhaustion: it is caused by dehydration and salt deficiency
- Burning: dry heat causes burning, and moist heat causes scalding.
During postmortem examination the body should be thoroughly examined to detect the actual causes of death.
Before death (antemortem):
- Presence of hyperemic patches and antemortem blisters,
- Presence of soot in the trachea, larynx, bronchus,
- And those blisters have red marginal linings and contains serum rich in proteins and chloride.
After death (postmortem):
- Parts of the body which are in the contact with the grounds do not show burning.
(Source: Ramesh Parajuli Library Notes at Kathmandu School of Law's Library, accessed in June 2024)
