Heat-related illness in the African wilderness

Abstract

Wilderness heat-related illnesses span a variety of conditions caused by excessive or prolonged heat exposure, and/or the inability to compensate adequately for increased endogenous production during strenuous outdoor activities. Despite management of well-known risk factors, such as lack of fitness or acclimatisation, dehydration, underlying illness and certain medications, even highly trained individuals may exceed their physiological capability to dissipate increased core temperature. Heat illnesses range from benign cramps to the more concerning heat syncope and exercise-associated collapse (with or without hyperthermia), and culminate in life-threatening heat stroke. The differential diagnosis in the wilderness is broad and should include exercise-associated hyponatraemia with or without encephalopathy. Clinical guidelines for wilderness and hospital management of these conditions are available. Field management and evacuation are based on severity, and include cooling, rehydration and assessment of core temperature and serum sodium, if possible. Hyponatraemia should be corrected with the use of oral or intravenous hypertonic saline, depending on whether the patient can safely take oral fluids. Hospital management may include aggressive and potentially invasive cooling, careful assessment for organ dysfunction, and intensive multi-organ support, if required. Paracetamol, non-steroidal anti-inflammatory drugs and dantrolene should not be used.