Heat illness or heat-related illness is a spectrum of disorders due to environmental heat exposure. There are two major categories: minor heat illness

[heat edema, prickly heat, heat syncope, heat cramps, and heat exhaustion] and major syndromes [heat stroke].

Heat Cramps

  • Involuntary, spasmodic contractions of skeletal muscles, usually of the calves, occasionally the thighs and shoulders.
  • Self-limited, no significant morbidity, patient’s chief complaint will be pain.
  • Due to relative deficiency of sodium, potassium, and fluid at a cellular level.
  • Treat with fluids and salt replacement PO or IV.
  • Complications: rarely rhabdomyolysis secondary to diffuse and protracted muscle spasm
  • Prevented by maintaining adequate salt intake and drinking commercial electrolyte beverages.

Heat syncope

  • Variant of postural hypotension resulting from the cumulative effect of relative volume depletion, peripheral vasodilatation, and decreased vasomotor tone.
  • Occurs in nonacclimatized individuals during the early stages of heat exposure.
  • Evaluation includes exclusion of metabolic, cardiovascular, and neurologic disorders that produce syncope.
  • Treat with rest, removal from the heat source, PO or IV rehydration.

Heat Exhaustion

  • Acute heat illness that reflects significant volume depletion and may or may not have an elevated core temperature.
  • Symptoms: weakness, malaise, lightheadedness, fatigue, dizziness, nausea, vomiting, frontal headache, and myalgias.
  • Clinical manifestations: orthostatic hypotension, sinus tachycardia, tachypnea, diaphoresis, and syncope, core temp can range from normal to 40°C.
  • Mental status remains normal.
  • Treat with volume, electrolyte replacement and rest.
  • Complications: can progress to heat stroke.

Heat Stroke

  • Core tem