Heat stroke consists of hyperthermia (greater than 105.8 degrees F [41 degrees C]), central nervous system dysfunction, and cessation of sweating with hot, dry skin. It is a medical emergency that results from failure of the thermo-regulatory mechanisms of the body. It has a high death rate and requires rapid reduction in body core temperature. Heat syncope is characterized by a transient loss of consciousness with peripheral vasodilation and decreased cardiac output with normal body temperature. Heat cramps involve painful contractions of large muscle groups because of decreased hydration and a decrease of serum sodium and chloride. Heat exhaustion is distinguished by a core temperature of less than 102.2 degrees F (39 degrees C) and an absence of central nervous system dysfunction. Hypernatremic heat exhaustion results from inadequate water replacement. The reference by Knochel et al. reviews some unusual etiologies of environmental-induced heat illnesses. The reference by Khosla et al. also reviews heat induced illnesses and their treatment.
Knochel JP. Environmental heat illness: An eclectic review. Arch Intern Med 1974;133:841-864
PMID:4821779 (Link to Abstract)
Hubbard RW, Gaffin SL, Squire DL. Heat related illness, in Wilderness Medicine, ed 3. St Louis, MO, Mosby, 1995, p 167
Khosla R, Guntupalli KK. Heat-related illnesses. Crit Care Clin 1999;15:251-263
PMID:10331127 (Link to Abstract)