Recognition

Recognition of heat syncope and ruling out a more serious condition is critical for the healthcare provider. There are various causes of collapse in an exercising individual; therefore the clinician’s primary goal is to rule out cardiac arrest or other life-threatening causes of collapse (i.e., exertional heat stroke, head injury, exertional sickling). Initial assessment of an athlete that has experienced syncope should include assessment of responsiveness, breathing, and heart rate [7]. Proper recognition of heat syncope consists of recognizing the symptoms, which may include dizziness, tunnel vision, a brief episode of fainting, and pale skin [7]. Once an acute cardiac etiology is ruled out, the clinician should ensure the patient is not experiencing exertional heat stroke. The key to ruling out exertional heat stroke is that with heat syncope, core body temperature will typically remain below 40 °C (104 °F), whereas with exertional heat stroke (EHS), patients will have a dangerously elevated core body temperature, often greater than 104 °F. Those with EHS will also have an altered mental status. After a fainting episode, patients typically regain a normal mental status. The treatment for these conditions is vastly different; therefore, ruling out more serious conditions and confirming the diagnosis of heat syncope is extremely important.

Treatment

Treatment for heat syncope is similar to other syncopal episodes. Once more serious metabolic, cardiovascular, or neurologic disorders have been ruled out (i.e., primary survey), the patient should be placed in the Trendelenburg position, and vital signs should be monitored. If possible, the patient should be moved to a cooler area (air-conditioned or shaded area), and fluids should be given orally when the patient has regained consciousness and is coherent [7]. Attempts to cool via nonaggressive cooling methods (i.e., fanning, ice towels) may improve the patient’s status; however, more aggressive cooling, such as cold water immersion, is not necessary since body temperature will not be dangerously elevated with heat syncope. Emphasis in treating a heat syncope patient should be placed on restoring cardiovascular function and ensuring signs and symptoms are no longer present.

Return to Activity

Return to exercise following heat syncope requires three important steps. Primarily, a more serious condition such as cardiac, EHS, or sickling should be ruled out. Secondly, healthcare providers should ensure all signs and symptoms from the syncopal episode have resolved. This would include normal vital signs, primarily blood pressure and heart rate, and restoration of normal hydration status. Lastly, the cause of the heat syncope should be determined and addressed prior to return to activity. If the patient lacked heat acclimatization prior to the syncopal episode, a gradual progression of heat exposure across 7–10 days should be introduced. The patient’s hydration status should be measured via body mass changes or urinary field markers, such as urine color or specific gravity, to ensure the patient is euhydrated prior to being reintroduced to the warm environment. Additionally, it is imperative to educate the patient on maintaining a proper diet. If any of the signs or symptoms has not resolved or heat syncope should reoccur, the patient should be referred for a more extensive follow-up with a physician.

Conclusion

Understanding the development, pathophysiology, recognition, and treatment of minor heat illnesses is important for medical professionals. While minor heat illnesses lack the severity associated with exertional heat stroke and other medical emergencies, treating minor heat illnesses appropriately can enhance the acclimatization process and prevent the development of exertional heat illnesses.