IMPORTANCE Heat exposure is known to have a complex set of physiological effects on multiple organ systems, but current understanding of the health effects is mostly based on studies investigating a small number of prespecified health outcomes such as cardiovascular and respiratory diseases. OBJECTIVES To identify possible causes of hospital admissions during extreme heat events and to estima...

Introduction: Extreme heat claims more lives than all other weather-related exposures combined. Hajj rituals at Mina, Arafat, and Muzdalifah involve a minimally-clothed, moving assemblage of 3.5 million pilgrims who are exposed to a harsh, hot, desert climate during physically challenging outdoor rituals and unsheltered night stays, rendering them prone to heat illness, dehydra...

Cerebellar Dentate Nuclei and Splenium on DiffusionWeighted MR Imaging Heat stroke is a critical illness characterized by hyperthermia (elevated core body temperature 40°C) with accompanying life-threatening complications. Previous MR imaging findings of heat stroke included diffuse atrophy of the cerebellum; hyperintense lesions in the cerebellum, external capsule and adjacent lateral putamen,...

Gut-derived endotoxin and pathogenic bacteria have been proposed to be important causative factors of morbidity and mortality due to heat stroke. However, the molecular mechanisms underlying the small intestinal lesions caused by heat stroke have yet to be well characterized. In order to verify the possible inflammatory pathogenesis of intestinal tissue injury, a mouse heat stroke model was est...

Exposure to high environmental temperature leading to increased core body temperature above 40°C and central nervous system abnormalities such as convulsions, delirium, or coma is defined as heat stroke. Studies in humans and animals indicate that the heat shock responses of the host contribute to multiple organ injury and death during heat stroke. Heme oxygenase-1 (HO-1)-a stress-responsive en...

INTRODUCTION Exertional heat stroke (EHS) is the most dangerous heat-related injury. EHS may be followed by a state of heat intolerance. The Israeli Defense Forces (IDF) performs heat tolerance tests (HTT) to all heat injury victims 6-8 wk following injury as part of the "return to duty" process. The HTT protocol and normal values are based on vast experience with young healthy men. Over the la...

Progressively increasing heat stress ultimately results in heat stroke, a medical emergency leading to death if not treated properly. Initially in heat stress, enormous increases in blood flow and volume in skin (and muscle if exercising) are achieved by the diversion of blood away from the splanchnic bed, kidneys, and probably fat and muscle, and in some species such as man, there is also an i...

Exertional heat illness typically occurs over hours in younger athletic patients or military recruits who exercise at elevated temperatures for a sufficient period of time to cause the rate of heat production to exceed the capacity of the body to dissipate heat. Since the physiological response to exercise includes cutaneous vasodilation and sweating, any limitation of such a response can cause...

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