Heat exhaustion occurs after prolonged heat exposure, usually over a period of hours to days. People who work in hot environments, older adults and the very young are at greater risk of developing heat exhaustion because they cannot or do not replace enough fluids to compensate for the amount of fluid lost from sweating.
Causes
According to "Current Diagnosis & Treatment Emergency Medicine," heat exhaustion can occur because of a primary water loss or from sodium loss. The primary water loss happens when a person in a hot environment does not drink enough water. Sodium or salt loss occurs when a person in a hot environment sweats excessively and then replaces the fluid loss with pure water.
Symptoms
Patients with heat exhaustion will have a sudden onset of extreme thirst, generalized weakness and muscle cramping. The patient will also experience a headache, vomiting and a fast heart rate. The combination of symptoms will eventually cause the patient to become unaware of her surroundings and collapse.
Body Temperature
"Sheehy's Emergency Nursing Principles and Practice" indicates that mild to severe temperatures may be seen in heat exhaustion, ranging from 98.6 to 105 degrees Fahrenheit. Excessive sweating of the skin may or may not be present. If left untreated, heat exhaustion can rapidly progress to heat stroke.
Treatment
The treatment for a patient with heat exhaustion starts with moving the patient to a cooler environment and removing any constricting clothing. If the patient's body temperature is extremely high, cool, moist cloths can be placed on the patient to help reduce his temperature. Patients will require fluid and electrolyte replacement. If the patient is able to drink, he should be given cool water and salted fruit drinks. If the patient is unable to drink fluids, he will need intravenous fluid replacement. Patients with heat exhaustion should be evaluated by a medical provider. Even if the patient is able to drink fluids, he still should be examined. Blood tests will be done to monitor the correction of the electrolyte imbalance.
Outcome
Hospital admission may be necessary for patients who are not improving within a few hours of fluid replacement. Any patient who has a history of cardiac disease may be observed closely with a heart monitor, because the loss of fluid and electrolytes can cause heart irregularities.
References
- "Current Diagnosis & Treatment Emergency Medicine"; C. Keith Stone and Roger Humphries; 2007
- "Sheehy's Emergency Nursing Principles and Practice"; Mosby Elsevier; 2009
