Heat & Cold InjuriesHeat & Cold Injuries

Heat Production & Heat Production & DissipationDissipation

Heat Production:Heat Production: Basal Metabolic Basal Metabolic

RateRate BMR is increased by BMR is increased by

shivering shivering

Heat Loss:Heat Loss: Conduction Conduction Convection Convection Evaporation Evaporation RespirationRespiration

Risk factors in heat illnessRisk factors in heat illness

Fitness and body mass indexFitness and body mass index Age Age Gender Gender Medical conditions Medical conditions Medications Medications

Heat Related DisordersHeat Related Disorders

Minor heat related Minor heat related disordersdisorders– Heat rashHeat rash– Heat edema Heat edema – Heat tetany Heat tetany – Muscle (Heat) Muscle (Heat)

cramps cramps – Heat syncope Heat syncope

Major heat related Major heat related disorders disorders – Exertion associated Exertion associated

collapse collapse – Heat Exhaustion Heat Exhaustion – Heat stroke Heat stroke

Heat RashHeat Rash

Known as prickly heat and miliaria rubra. Known as prickly heat and miliaria rubra. It is a red, pruritic, papular rash normally It is a red, pruritic, papular rash normally

seen on the skin an area of restrictive seen on the skin an area of restrictive clothing and heaving sweating. clothing and heaving sweating.

It caused by inflammation of sweet It caused by inflammation of sweet glands that blocks the sweet ductglands that blocks the sweet duct

Management: by cooling and drying the Management: by cooling and drying the affected area and by preventing further affected area and by preventing further conditions that cause sweet in these conditions that cause sweet in these areas. areas.

Heat EdemaHeat Edema

It is a mild, dependent edema in the It is a mild, dependent edema in the hands, feet, and ankles seen in early hands, feet, and ankles seen in early stages of heat acclimatization. stages of heat acclimatization.

Edema does not indicate excessive Edema does not indicate excessive fluid intake or cardiac, renal or hepatic fluid intake or cardiac, renal or hepatic disease. disease.

It is self limiting It is self limiting Management: loosening clothes and Management: loosening clothes and

elevating the legs, diuretics are not elevating the legs, diuretics are not indicated. indicated.

Heat Tetany Heat Tetany

It is rare and self limiting condition that It is rare and self limiting condition that occur in patients acutely exposed to occur in patients acutely exposed to short intense, heat conditions. short intense, heat conditions.

The principal cause is hyperventilation.The principal cause is hyperventilation. S & S: respiratory alkalosis, S & S: respiratory alkalosis,

paresthesia, carpopedal spasm and paresthesia, carpopedal spasm and tetany. tetany.

Management: removal from source of Management: removal from source of heat, and controlling hyperventilation. heat, and controlling hyperventilation.

Muscle (Heat) Cramps Muscle (Heat) Cramps

They are short term, painful muscle They are short term, painful muscle contractions frequently seen in the contractions frequently seen in the calf muscle an the voluntary muscles calf muscle an the voluntary muscles of abdomen and extremities. of abdomen and extremities.

They occur during exercise. They occur during exercise. Management: rest in cool Management: rest in cool

environment, stretching the affected environment, stretching the affected muscle, and consuming oral fluids. muscle, and consuming oral fluids.

Heat SyncopeHeat Syncope

It occurs with prolonged standing in It occurs with prolonged standing in warm environments and is caused by warm environments and is caused by low blood pressure. low blood pressure.

Heat causes vasodilatation and Heat causes vasodilatation and venous blood pools in the legs. venous blood pools in the legs.

Management: removal to cool Management: removal to cool environment, oral or IV rehydration. environment, oral or IV rehydration.

Exertion Associated Exertion Associated CollapseCollapse

It occurs when individual collapses It occurs when individual collapses after strenuous exercise. after strenuous exercise.

S & S: nausea, lightheadedness and S & S: nausea, lightheadedness and collapse, postural hypotension, collapse, postural hypotension, profuse sweaty, rapid pulse and profuse sweaty, rapid pulse and ventilations, normal or slightly ventilations, normal or slightly elevated body temperature.elevated body temperature.

Management: remove to cool Management: remove to cool environment, rest, oral or IV environment, rest, oral or IV rehydration.rehydration.

Heat ExhaustionHeat Exhaustion It is the most common heat related disorder. It is the most common heat related disorder. It results from cardiac output insufficient to It results from cardiac output insufficient to

support the increased circulatory load. support the increased circulatory load. It is a diagnosis of exclusion when there is no It is a diagnosis of exclusion when there is no

evidence of heat stroke. evidence of heat stroke. S & S: decreased urine output, frontal headache, S & S: decreased urine output, frontal headache,

drowsiness, euphoria, nausea, lightheadedness, drowsiness, euphoria, nausea, lightheadedness, anxiety, fatigue and apathy. Postural anxiety, fatigue and apathy. Postural hypotension, profuse sweaty, rapid pulse and hypotension, profuse sweaty, rapid pulse and ventilation.ventilation.

Management: remove to cool environment, Management: remove to cool environment, supine resting position, remove restrictive heat supine resting position, remove restrictive heat dissipation, oral or IV rehydration and transfer. dissipation, oral or IV rehydration and transfer.

Heat Stroke Heat Stroke

It the most emergent and life threatening It the most emergent and life threatening from heat illness. from heat illness.

It is abnormal form of hyperthermia resulting It is abnormal form of hyperthermia resulting on a total failure of autoregulatory system. on a total failure of autoregulatory system.

S & S: hot flushed skin, tachycardia, elevated S & S: hot flushed skin, tachycardia, elevated body temperature, CNS dysfunction resulting body temperature, CNS dysfunction resulting in convulsions or coma. in convulsions or coma.

Management: ABC, cooling (passive or Management: ABC, cooling (passive or active) active)

Predisposing factors of Predisposing factors of hypothermiahypothermia

Injuries Injuries Chronic illness Chronic illness Shock Shock Burns Burns Head and spinal cord injuries Head and spinal cord injuries Generalized infection Generalized infection Diabetes Diabetes Unconscious patient Unconscious patient Aged people Aged people

Cold Injuries Cold Injuries

Minor cold related Minor cold related injuriesinjuries– Contact freeze Contact freeze

injury injury – Frostnip Frostnip – Cold urticaria Cold urticaria – Chilblains (pernio) Chilblains (pernio) – Solar keratitis Solar keratitis

( Snow Blindness) ( Snow Blindness)

Major cold related Major cold related disorders disorders – Localized cutaneous Localized cutaneous

cold injury cold injury – Nonfreezing cold Nonfreezing cold

injury injury – Freezing cold injury Freezing cold injury – Accidental Accidental

hypothermia hypothermia – Immersion Immersion

hypothermia hypothermia

Contact Freeze InjuryContact Freeze Injury

Caused by contact of unprotected Caused by contact of unprotected skin with cold material. skin with cold material.

Frostnip Frostnip

It is a precursor to frostbite. It is a precursor to frostbite. It produces reversible signs of of skin It produces reversible signs of of skin

blanching and numbness in localized blanching and numbness in localized tissue. tissue.

Seen on areas of the face, nose and Seen on areas of the face, nose and ears. ears.

It is self limiting tissue damage. It is self limiting tissue damage.

Cold UrticariaCold Urticaria

It is characterized by rapid onset of It is characterized by rapid onset of itchiness, redness, and swelling of itchiness, redness, and swelling of skin after exposure to cold.skin after exposure to cold.

It caused by released of histamine. It caused by released of histamine. Treatment includes avoiding cold and Treatment includes avoiding cold and

use of antihistamines. use of antihistamines.

Chilblains (Pernio)Chilblains (Pernio)

They are small skin lesions that are itchy They are small skin lesions that are itchy and tender, red or purple bumps that and tender, red or purple bumps that occur on the extensor skin surface of the occur on the extensor skin surface of the finger or any skin surface from chronic finger or any skin surface from chronic cold exposure. cold exposure.

They occur several hours after to the cold.They occur several hours after to the cold. Symptoms will subside with elimination of Symptoms will subside with elimination of

cold.cold. Management: protection from cold and Management: protection from cold and

appropriate gloves and clothing.appropriate gloves and clothing.

Solar Keratitis (Snow Solar Keratitis (Snow Blindness)Blindness)

It is caused by reflection ultraviolet It is caused by reflection ultraviolet rays to skin and eyes. rays to skin and eyes.

S & S: excessive tearing, pain, S & S: excessive tearing, pain, redness, swollen eye lids, headache redness, swollen eye lids, headache and hazy visionand hazy vision

Management: patching affected eye, Management: patching affected eye, antibiotics and analgesics. antibiotics and analgesics.

Localized Cutaneous Cold Localized Cutaneous Cold InjuryInjury

They occur at peripheral sites on the They occur at peripheral sites on the bodybody

It classified into:It classified into:– Freezing (Frostbite)Freezing (Frostbite)– Nonfreezing (immersion) Nonfreezing (immersion)

Nonfreezing Cold InjuryNonfreezing Cold Injury

It is a syndrome called Trench Foot It is a syndrome called Trench Foot or Immersion Foot. or Immersion Foot.

It results from damage to peripheral It results from damage to peripheral tissues.tissues.

S & S: edema, pale, pulseless and S & S: edema, pale, pulseless and immobile.immobile.

Management: eliminate further Management: eliminate further cooling, prevent further injury, cooling, prevent further injury, analgesics, transportanalgesics, transport

Freezing Cold InjuryFreezing Cold Injury

It involves tissue destruction and It involves tissue destruction and possible loss. possible loss.

Most common areas are nose, ears, Most common areas are nose, ears, hands, fingers, feet, toes. hands, fingers, feet, toes.

Management: support, cover, Management: support, cover, analgesics, IV fluids. analgesics, IV fluids.

Accidental HypothermiaAccidental Hypothermia

It is a generalized hypothermia. It is a generalized hypothermia. It is divided into:It is divided into:

– Primary hypothermia Primary hypothermia – Secondary hypothermia Secondary hypothermia

S & S: depends on the stage and S & S: depends on the stage and core body temperature. core body temperature.

Management: Management:

Immersion HypothermiaImmersion Hypothermia

It is a generalized hypothermia. It is a generalized hypothermia. S & S: depends on the stage and S & S: depends on the stage and

core body temperature. core body temperature. Management: ABC, prevent further Management: ABC, prevent further

heat loss, IVF, transport. heat loss, IVF, transport.

Prevention of cold weather & Prevention of cold weather & heat injuriesheat injuries

Think of the acronym COLDThink of the acronym COLD C-Clean clothesC-Clean clothes O-Avoid OverheatingO-Avoid Overheating L-Loose Layers of clothingL-Loose Layers of clothing D-Keep DryD-Keep Dry

Change your socks