Which of the following are characteristics that differentiate between heat exhaustion and heat stroke? Select All that Apply.

Choice A rationale Heat exhaustion is characterized by the body's attempt to dissipate heat, often leading to significant fluid and electrolyte loss through diaphoresis. This depletion of intravascular volume frequently results in orthostatic hypotension and a compensatory tachycardia as the heart attempts to maintain cardiac output. These cardiovascular changes are hallmark signs of the transition from mild heat stress to exhaustion. Normal heart rates are 60 to 100 beats per minute, while tachycardia exceeds 100. Choice B rationale This statement is scientifically inaccurate because hot, dry skin is a definitive characteristic of heat stroke, not heat exhaustion. In heat exhaustion, the thermoregulatory mechanisms are still functioning, so the skin is usually pale, cool, and clammy due to heavy sweating. Heat stroke occurs when the sweat glands fail or the body can no longer evaporate sweat effectively, leading to a cessation of diaphoresis. Consequently, the skin becomes hot, flushed, and dry to the touch. Choice C rationale A critical differentiator between the two conditions is the presence of neurological impairment. Heat stroke involves severe hyperthermia that causes thermal injury to the brain, manifesting as confusion, agitation, seizures, or coma. In contrast, heat exhaustion typically presents with intact mental status, though the individual may feel dizzy or weak. Any patient showing altered mental status in a high heat environment must be treated for heat stroke until proven otherwise to prevent permanent brain damage. Choice D rationale Heat exhaustion involves active thermoregulation where the body tries to cool itself through maximal diaphoresis. This leads to the physical finding of skin that is damp, cool, or clammy. The patient loses large amounts of sodium and water, contributing to the symptoms of fatigue and nausea. Recognizing excessive sweating as a symptom of exhaustion is vital, as it indicates the body is still attempting to compensate, whereas the absence of sweat indicates a progression to heat stroke.