Contributor: Megan Hurley, MD

Educational Pearls:

Lightheadedness, hypotension, and/or syncope in patients with peripheral vasodilation due to heat exposure
Treatment is removal from the heat source and rehydration (IV fluids or Gatorade)

Patients have elevated body temperature (greater than 38º C but less than 40º C)
Symptoms include nausea, tachycardia, headache, sweating, and others
Normal mental status or mild confusion that improves with cooling
Treatment is removal from the heat source and hydration

From prolonged exposure to heat
Defined as a core body temperature > 40.5º C, though not required for diagnosis or treatment
Presentation is similar to heat exhaustion with the addition of neurological deficits including ataxia
Patients present “dry”

Prolonged exposure to heat during exercise
Similar to classic heat stroke but the patients present “wet” due to antecedent treatment in ice baths or other field treatments

Cooling
Rehydration
Evaluation of electrolytes
Antipyretics are not helpful because heat-induced illnesses are not due to hypothalamic dysregulation

References

Casa DJ, McDermott BP, Lee EC, et al. Cold water immersion: the gold standard for exertional heatstroke treatment. Exerc Sport Sci Rev 2007; 35:141.
Ebi KL, Capon A, Berry P, et al. Hot weather and heat extremes: health risks. Lancet 2021; 398:698.
Epstein Y, Yanovich R. Heatstroke. N Engl J Med 2019; 380:2449.
Gardner JW, JA K. Clinical diagnosis, management, and surveillance of exertional heat illness. In: Textbook of Military Medicine, Zajitchuk R (Ed), Army Medical Center Borden Institute, Washington, DC 2001.
Khosla R, Guntupalli KK. Heat-related illnesses. Crit Care Clin 1999; 15:251.
Lipman GS, Gaudio FG, Eifling KP, et al. Wilderness Medical Society Clinical Practice Guidelines for the Prevention and Treatment of Heat Illness: 2019 Update. Wilderness Environ Med 2019; 30:S33.

Summarized by Jorge Chalit, OMSIII | Edited by Meg Joyce, MS1

Episode 917: Heat-Related Illnesses

Emergency Medical Minute