Heat syncope


  • Variant of postural hypotension[1]
    • Results from combination of volume depletion, decreased vasomotor tone and peripheral vasodilatation
    • Often precipitated by rapid change in position during exercise
    • Occurs in nonacclimatized patients during early stages of heat exposure (especially elderly)

Clinical Features

  • Syncope in the setting of environmental heat exposure

Differential Diagnosis

Environmental heat diagnoses

Syncope Causes


  • Diagnosis of exclusion


  • Supine position
  • Remove patient from heat source
  • Give PO or IV rehydration


  • Hospitalization usually not necessary

See Also


  1. Waters T. Heat Emergencies In: Tintinalli's Emergency Medicine: A Comprehensive Study Guide. 7th ed. McGraw Hill Medical. 2011: 1339