Heat-Related Illness and Heatstroke: A Narrative and Clinical Review for Emergency Clinicians

Heat-related illness is a spectrum of conditions that can have a high rate of morbidity and mortality. This review highlights the pearls and pitfalls of heat-related illness, particularly heatstroke, including presentation, diagnosis, and management in the emergency department based on current evidence. Heatstroke represents the most severe form of heat-related illness and is characterized by core temperature above 40°C with central nervous system dysfunction. Both classic and exertional forms share similar pathophysiology driven by thermoregulatory failure, systemic inflammation, and multiorgan injury. Emergency department management centers on rapid recognition and immediate cooling, as outcomes correlate with duration and magnitude of hyperthermia. Cold-water immersion remains the gold standard for rapid cooling; however, evaporative and conductive methods such as ice sheets, tepid water misting with fanning, and administration of chilled IV fluids are effective alternatives when immersion is impractical. Continuous core temperature monitoring is essential to avoid overcooling, with a target of 39°C. Sedation should be achieved chemically rather than through physical restraint to prevent further heat generation, and vasopressors should be avoided unless hypotension persists despite aggressive cooling and volume resuscitation. Diagnostic testing should not delay cooling, though evaluation for multiorgan dysfunction and mimics such as sepsis or toxicologic causes is critical. In conclusion, an understanding of heat-related illness and heatstroke can assist emergency clinicians in diagnosing and managing this potentially deadly disease.