Chapter 21: Effects of Cold and Heat

Trauma

and death from hyperthermia or heat is due to the exposure to heat, derived from:

Thermal injury

defined as an injury to the body resulting from localized or generalized exposure to extremes of temperature due to various etiological factors.

Heat load

It is the sum of heat generated by the oxidation of metabolic products and heat acquired from the environment around. It has three mechanisms:

Insensible heat loss

this is due to the continued diffusion of water molecules through the skin and respiratory surfaces regardless of the body temperature.

Thermal injury

defined as an injury to the body resulting from localized or generalized exposure to extremes of temperature due to various etiological factors

Insensible heat loss

this is due to the continued diffusion of water molecules through the skin and respiratory surfaces regardless of the body temperature

Hypothermia

when an individuals body temperature is below 95°F (35°C)

Frostbite

a syndrome complex comprising of local tissue necrosis

Hyperthermia

an acute condition that occurs when the body produces or absorbs more heat than it can dissipate

Heat hyperpyrexia

rectal temperature above 41 degrees

Heat stroke

it is due to the impairment of the heat regulation mechanism in the body, especially resulting in the death of the victim due to the paralysis of medullary centers

Scalds

trauma resulting from the application of moist heat commonly involving only superficial layers of the skin

Vesication

Also called blister formation is chiefly due to increased capillary permeability, and this needs a few minutes to develop

Superficial Burns

These burns are usually red, moist, and very painful

Heat loss by sweating

In cold weather, the sweating is essentially zero, while in hot weather it is maximum.

Hypothermia

when an individual’s body temperature is below 95°F (35°C). This will occur when the loss of body heat exceeds heat production.

Trench Foot

Due to exposure to cold (5-8 C) coupled with dampness and there will be no tissue freezing.

Frostnip

The skin turns white and waxy or gray in color and mottled, but feels normal to touch.

Frostbite

It follows then when no treatment is given at the initial phase of frostnip. Ice crystals are then formed in the skin and deeper tissues, which can exert osmotic force, causing water to move from intercellular space.

Frostbite

• A syndrome complex comprising of local tissue necrosis.
  • It commonly occurs in soldiers in winter warfare hiding in the trenches or in a shipwreck in Antarctic waters, etc.

Hyperthermia

an acute condition that occurs when the body produces or absorbs more heat than it can dissipate. It is usually due to excessive exposure to heat.

Mid-dermal Burns

• The outermost layer of skin is lost, as well as parts of the dermis (the next layer of skin).
• The burn is pink in color, with small white patches.
• The skin still blanches on pressure and is painful.

Deep-dermal burns

• Here there is deeper dermal destruction.
• The burn appears white and does not blanched on pressure.
• The skin is less sensitive and takes a longer period of time of heal, with scarring.

Full-thickness burns

This extend deep down into the dermis. The burn is leathery, ranges in color from white/grey/black, and is non-painful.

Heat cramps

The victim here complains of severe painful spasms in the voluntary muscles of the body due to excessive perspiration and loss of body electrolytes.

Heat stroke

it is due to the impairment of the heat regulation mechanism in the body, especially resulting in the death of the victim due to the paralysis of medullary centers. The syndrome complex may present in two forms:

acute

An _ form of heat stroke with sudden onset without any prodromal symptoms.

gradual onset

A of heat stroke forms with definite prodromal symptoms.

Superficial Burns

These burns are usually red, moist, and very painful. The outermost layer of the skin is involved (the epidermis) and there may be blisters present.

Scarring

It is usually more with burns due to dry heat. It would be present in cases involving the dermis. Burns involving only epidermis will heal without scar formation.

Vesication

Also called blister formation is chiefly due to increased capillary permeability, and this needs a few minutes to develop.

Necrosis of dermis

This results when deeper layers of skin are involved.

Erythema

This is the reddening of the skin which appears at once as the moist heat is applied.

Hydration

It is of paramount importance in cooling the victim. This is achieved by drinking water.

Curling’s ulcer

It is a rare sequel of severe burns, seen in the duodenum. It is due to tissue hypoxia and capillary endothelial damage.

Primary (neurogenic)

This shock is due to fear, severe pain, injury to, vital organs leading to death within 24 to 48 hours

Secondary (vascular)

This shock is due to loss of serum from burnt area — developing depletion of blood volume and hypovolemic shock, leading to death within 24 to 48 hours.

Coma

It occurs due to congestion of the brain and serious effusion into ventricles.

Asphyxia

It causes suffocation due to the inhalation of smoke or gasps of combustion.

Inflammation of Internal Organs

These are inflammation leading to meningitis, peritonitis, pneumonia, bronchitis, pleurisy, enteritis, and Curling’s ulcer in the duodenum.

Gangrene

Complications connected with the ulcers produced by burn such as gangrene, erysipelas, tetanus, profuse hemorrhage on separation of the slough, etc.

Toxemia

occurs due to the absorption of histamine formed as a result of the combustion of tissue.

Hepatorenal Syndrome

In every case of burns of any severity, absorption of altered protein occurs and this in turn leads to cellular damage to the liver and kidneys.

Pugilistic attitude

It is a condition wherein the body assumes a rigid position with the limbs flexed and resembles a boxer in defending position.