Environmental Emergencies The body gains and loses heat

Environmental Emergencies

The body gains and loses heat two ways: 1. From within the body itself 2. By contact with the external environment

Thermal Gradient The difference in temperature between the environment and the body. If the ambient temperature is warmer than the body, then heat flows from the environment to the body. If the ambient temperature is colder than the body, then heat flows from the body to the environment.

Other factors that effect heat gain and loss l l Wind relative humidity (the percentage of water vapor in the air.

Thermolysis Loss of heat from the body

The transfer of heat from the body into the environment occurs through the following 5 mechanisms: l Respiration l Evaporation l Convection l Conduction l Radiation

Hyperthermia State of unusually high body temperature

As the body attempts to eliminate excessive heat you will see general signs of thermolysis (heat loss) l l l Diaphoresis (sweating) Increased skin temperature Flushing

Predisposing Factors l Age of patient l Health of patient Diabetics are more prone Pediatric and geriatric patients heat regulating mechanisms are not as responsive as young adults and adults. to hyperthermia because they develop autonomic neuropathy. A condition that interferes with thermoregulatory input and with vasodilatation and perspiration. l l Medications Length of acclimatization

Predisposing Factors Cont…. . l l l Length of exposure Intensity of exposure Environmental factors such as humidity and wind

Preventative measures l l l Maintain adequate fluid intake Allow time for gradual acclimatization Limit exposure to hot environment

Specific Heat Disorders

What is sweating? Sweating occurs as sodium (salt) is transported to the skin. Because “water follows sodium” water is deposited on the skin surface evaporation occurs, aiding in the cooling process.

Sweating Cont…. . Since sweating involves not only the loss of water, but also the loss of electrolytes (sodium), intermittent cramping of skeletal muscle may occur.

Heat (muscle) Cramps Acute painful spasms of the voluntary muscles following strenuous activity in a hot environment without adequate fluid or salt intake.

Signs and Symptoms l l l Present with cramps in fingers, arms legs, or abdominal muscles Mentally alert with a feeling of weakness May feel dizzy or faint Vital signs stable Skin moist and warm

Treatment l l l Remove patient from the environment Place in a cool environment (shade or air conditioning) Administer a sports drink or 4 tsp of salt dissolved in 1 gallon of water. Massage painful muscles Apply cool moist cloth over forehead and over cramped muscles

Heat Exhaustion A mild heat illness; an acute reaction to heat exposure.

Signs and Symptoms l l l Increased body temperature ( >100 F) Skin cool and clammy with heavy perspiration Breathing rapid and shallow Weak pulse May develop diarrhea and muscle cramps Patient may feel weak

Signs and Symptoms Cont. . . l l l May lose consciousness Headache Anxiety Paresthesia (numbness) Impaired judgement Psychosis

Treatment l l Call 911 Remove patient from the environment. Place the patient in a supine position. Administer oral saline or a sports drink (administer fluids only if patient is conscious)

Tx. Cont…. l Remove some clothing from the patient and fan. If the patient begins to shiver stop fanning l Treat for shock

Symptoms should resolve with fluids, rest, and supine posturing with knees elevated. If they do not, consider that the symptoms may be due to an increased core body temperature which is predictive of impending heat stroke.

Heatstroke Acute dangerous reaction to heat exposure, characterized by a body temperature usually above 105° F and central nervous system disturbances.

Signs and Symptoms l l l Cessation of sweating Skin that is hot and dry Very high core temperature Deep respirations that become shallow, rapid at first but may later slow Rapid full pulse, may slow later

Signs and Symptoms l l l Hypotension with low or absent diastolic reading Confusion, disorientation, or unconsciousness Possible seizures

Tx l l l Call 911 Remove pt from the environment Initiate rapid active cooling, remove clothing cover the patient with sheets soaked in TEPID water. Avoid over cooling target core temp 102°F

Tx. Cont…. l Administer fluid therapy if and only if pt is able to swallow

Dehydration in Heat Disorders Dehydration often goes hand in hand with heat disorders because it inhibits vasodilation therefore thermolysis.

Signs and Symptoms of Dehydration l l l Nausea, vomiting, and abdominal distress Vision disturbances Decreased urine output Poor skin turgor Signs of hypovolemic shock Thirst is a poor indication of the degree of dehydration present