Heat Stroke

Abstract

Heat stroke is the most dangerous heat-related illness, and it can be fatal.Two characteristics define heat stroke: a core body temperature greater than 104°F (40°C) and neurological signs such as confusion, seizures, or loss of consciousness.Some of the first cells in the body to be affected are in the brain. These cells are sensitive to temperature changes. The heart also must work harder to push blood to the skin. As a person's temperature gets closer to the air temperature, the rate of heat transferred to the skin decreases. Evaporation of sweat also decreases with higher humidity. Sweating leads to further dehydration and loss of electrolytes and minerals vital for muscle and nerve cell function. As the body is no longer able to cool itself by sweating, heart rate and breathing increase to compensate. This can be aggravated by medications that alter heart function or by chronic diseases.Classic heat stroke is seen in people who are exposed to a hot environment, especially in young and elderly persons. Those with chronic diseases such as Parkinson disease, heart failure, or diabetes or who take medications can have a decreased response to dehydration. Exertional heat stroke is seen in healthy people who undergo strenuous activity in hot weather, such as marathon runners, military trainees, and football players.

Expert consensus on the diagnosis and treatment of heat stroke in China

“…The brain is one of the most easily affected organs in the early stage of HS, and it recovers slowly. The incidence rate of permanent nerve injury among surviving patients is 20%-30% [96]. The detailed mechanism of central nervous system injury is still not clear, and currently, it is believed to be related with the following mechanisms [46, 97-100]: 1) direct damage by high heat -The central nervous system is sensitive to heat toxicity, with the most vulnerable parts being the cerebellum and cerebral cortex; 2) secondary hypoxia -convulsions, aspiration and asphyxia in HS patients are likely to lead to hypoxia of the brain and are potential factors that aggravate brain damage; 3) ischemic necrosis -microthrombus formation caused by elevated intracranial pressure and decreased cerebral blood flow can lead to extensive ischemic brain damage; 4) secondary bleeding -severe coagulopathy or inappropriate anticoagulant therapy can cause cerebral hemorrhage.…”

Mesenchymal Stem Cells Regulate Activation of Microglia Cells to Improve Hippocampal Nerve Damage of Heat Stroke Rats

“…Clinically, heat stroke is characterized by CNS dysfunction, multi-organ failure and sharp elevation of body temperature (usually > 40.5 °C) (1)(2)(3)(4). At present, there is no uniform and objective diagnostic criterion for diagnosis of heat stroke.…”

“…As global warming is intensi ed year by year, the incidence of heat stroke increases signi cantly (1,2). Thermal radiation can result in systemic in ammatory response syndrome, which leads to multiple organ failure, with a fatality rate as high as 50%-60% (3,4).…”

Quantifying the impact of changing the threshold of New York City heat emergency plan in reducing heat-related illnesses

“…Yet, it also important to consider heat impacts on morbidity outcomes that may be a more relevant early indicator to monitor heat-related health impacts. Particularly, it is possible to use heatstroke and related ICD diagnoses as indicators of the many heat-related health outcomes (Bobb et al 2014, Peiris et al 2017, although many other health outcomes can occur from extreme heat (see: http:// blr.hcpro.com/content.cfm?content_id=307085) Original content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence.…”