The body's ability to regulate core temperature depends on both host (internal) and environmental (external) factors. Although athletes are commonly thought to be most at risk for
heat illnesses, children and the elderly are particularly vulnerable.
Heat cramps, which are caused by fluid and
electrolyte imbalances, are treated with
massage, and fluid and
electrolyte replacement.
Heat exhaustion occurs both as water- and
sodium-depleted types, with associated symptoms such as malaise,
vomiting, and
confusion. Treatment involves taking the affected person to a cool environment and replacing fluids and
electrolytes if needed. In more serious cases, intravenous hydration may be necessary, although monitoring of serum
sodium levels is important to prevent
cerebral edema. If not treated promptly,
heat exhaustion may evolve into
heatstroke, a deadly form of
heat illness.
Heatstroke occurs in classic and exertional forms and is present when the core body temperature exceeds 40 degrees C (104 degrees F). The patient may experience
cardiac arrhythmias,
rhabdomyolysis, serum chemistry abnormalities,
disseminated intravascular coagulation, and death.
Heatstroke is a medical emergency that should be treated immediately with temperature-lowering techniques such as immersion in an
ice bath or evaporative cooling. Fluid
resuscitation is important but should be closely monitored, and renal function may need to be protected with
mannitol and
diuretics. It is important to be vigilant for
heat illnesses because they occur insidiously but progress rapidly.