injuries poisoning
Heatstroke
Introduction
Heatstroke is hyperthermia accompanied by a systemic inflammatory response causing multiple organ dysfunction that may result in death. Symptoms include temperature>40° C and altered mental status; sweating may be absent or present. Diagnosis is clinical. Treatment includes rapid external cooling, IV fluid resuscitation, and support as needed for organ dysfunction. Heatstroke occurs when compensatory mechanisms for dissipating heat fail and core temperature increases substantially. Inflammatory cytokines are activated, and multiple organ dysfunction may develop. Organ dysfunction may occur in the central nervous system (CNS), skeletal muscle ( Rhabdomyolysis ), liver, kidneys, lungs (acute respiratory distress syndrome), and heart. Heatstroke is sometimes divided into 2 variants, although the usefulness of this classification is controversial (see table): Classic Exertional Classic heatstroke takes 2 to 3 days of exposure to develop. It occurs during summer heat waves, typically in older, sedentary people with no air-conditioning and often with limited access to fluids. It can occur rapidly in children left in a hot car, particularly with closed windows. Exertional heatstroke occurs more abruptly and affects healthy active people (eg, athletes, military recruits, factory workers). It is a common cause of death in young athletes. Intense exertion in a hot environment causes a sudden massive heat load that the body cannot modulate. Rhabdomyolysis is common; Acute Kidney Injury (AKI) and coagulopathy are somewhat more likely and severe. Characteristic Characteristic Classic Heatstroke Classic Heatstroke Exertional Heatstroke Exertional Heatstroke Onset 2–3 days Hours Patients usually affected Older, sedentary people Healthy active people (eg, athletes, military recruits, factory workers) Risk factors No air-conditioning during summer heat waves Intense exertion, particularly without acclimatization Skin Usually hot and dry but sometimes moist with sweat Often moist with sweat Heatstroke may occur after using stimulant drugs (eg,cocaine, phencyclidine [PCP], amphetamines), monoamine oxidase inhibitors, or anticholinergic medications (eg, antihistamines, antimuscarinics) that cause a hypermetabolic state or impair the ability to sweat. Usually, an overdose is required, but exertion and environmental conditions can be additive. (See also Overview of Heat Illness .) 