Pathophysiology and management of heat illness

The frequency and intensity of heat waves are currently increasing due to climate change. Hence more cases of heat illness are being observed, a potentially life-threatening disease, which requires rapid and expert management. An overview of the pathophysiology and acute management of heat illness is presented. Analysis and evaluation of important, recently published contributions, studies, and reviews regarding heat illness without claim for completeness or fulfilling the criteria for a 'systematic meta-analysis'. Presentation of a recommended clinical-practical classification and management of heat illness in emergency departments or intensive care units. The manifestation of heat illness arising from prolonged exposure to heat prevaries (heat cramps, heat edema, heat exhaustion, heat stroke). The main pathophysiologic mechanisms are disruption of thermoregulation, peripheral vasodilation of the skin surface, hypoperfusion of visceral organs, and brain, and cardiac stress. Uncompensated heat stress can result in multiorgan dysfunction/failure syndrome due to the initiation of cytokine pathways, specifically in at-risk and/or chronically ill patients. The manifestation of uncompensated heat stroke is associated with a hospital mortality > 50%. Rapid identification, classification and targeted management are crucial for the outcome, in particular the initiation of adequate cooling measures. In the future, increasing numbers of patients suffering from prolonged heat exposure will require treatment in emergency departments and intensive care units. Sufficient professional knowledge regarding pathophysiology and management are decisive for successful therapy. Hence, the topic heat illness should be implemented in training and education.