Heat exhaustion

Heat exhaustion is a heat-related illness characterized by the body's inability to effectively cool itself, typically occurring in high ambient temperatures or during intense physical exertion. In heat exhaustion, core body temperature ranges from 37 °C to 40 °C (98.6 °F to 104 °F). Symptoms include profuse sweating, weakness, dizziness, headache, nausea, and lowered blood pressure, resulting from dehydration and serum electrolyte depletion. Heat-related illnesses lie on a spectrum of severity, where heat exhaustion is considered less severe than heat stroke but more severe than heat cramps and heat syncope.^[1]

Climate change and increasing global temperatures have led to more frequent and intense heat waves, raising the incidence of heat exhaustion. Risk factors include hot and humid weather, prolonged heat exposure, intense physical exertion, limited access to water or cooling, and certain medications that can exacerbate fluid and serum electrolyte losses including diuretics, antihypertensives, anticholinergics, and antidepressants. Children, older adults, and individuals with certain pre-existing health conditions are more susceptible to heat exhaustion due to their reduced ability to regulate core body temperature.^[1][2][3]

Prevention strategies include wearing loose and lightweight clothing, avoiding strenuous activity in extreme heat, maintaining adequate hydration, and gradually acclimatizing to hot conditions. Public health measures, such as heat warnings and community cooling centers, also help prevent heat exhaustion during extreme weather events. Treatment involves moving to a cooler environment, rehydrating, and cooling the body. Untreated heat exhaustion can progress to heat stroke, a life-threatening condition characterized by a core body temperature above 40 °C (104 °F) and central nervous system dysfunction.^[4][5]