The Student Athlete: Heat stroke and other heat-related illnesses.
What is Heat stroke?
Heat stroke is a neurological disorder that results from the maladaption of one’s body to extreme temperatures leading to symptoms that are thought to be related to inflammatory response, poor blood flow to the brain and other organs and abnormal electrolyte/fluid balance. Heat stroke represents the most severe end of the heat related illness spectrum, while it is often brought up in the context of sports, it can impact anyone exposed to extreme heat. The medical definition of heat stroke is a core body temperature that is equal to or greater than 40C (104F), by rectal temperature, with the presence of abnormal CNS functions ( i.e. altered mental status, LOC, seizures etc)
Prior to the development of symptoms of heat stroke, one may develop signs of other heat related illnesses. Heat related illness spectrum includes:
Heat Cramps: muscle pain and cramping associated with strenuous exercise without signs of more severe injury.
Heat Syncope: light headed leading to passing out in the setting of hot/humid weather or prolonged exercise. Low heart rate, pallid, sweaty,
Heat Exhaustion: Extreme fatigue impacting ability to continue with physical activity and elevated core temperature ( >38C), but does not exhibit any signs of CNS dysfunction as would be noted in heat stroke.
Heat injury: No CNS dysfunction but presents with elevated core body temperature and signs of other end organ dysfunction. Signs and symptoms include exercise/heat related syncope and laboratory signs of injury to the liver (LFTs) kidney (Cr) and/or muscle (CK).
What are the risks for heat stroke (and other heat-related illnesses)?
The young and elderly are at increased risk
Those engaged in prolonged physical activity in hot ± humid weather
Those not physically conditioned or obese
Those that are not use to the climate conditions
Those who are sick
Those wearing clothes that are non-breathable
Medications or medical conditions that impair sweating (i.e. anticholinergics, atihistamines, antiepileptics )
Medications or medical conditions that increase loss of fluid ( i.e. diuretics)
Those whom are dehydrated
What are the symptoms of heat stroke?
Core Temperature >/=40C(104F)
Confusion, abnormal behavior, lethargy, seizure, coma, headache (CNS dysfunction)
Light headed
Rapid heart rate
Increased breathing rate
Dry warm skin or excessive sweat
Weakness
Muscle cramps
How is heat stroke (and other heat related illnesses) treated?
The central focus of heat stroke and other heat related illness therapy is prompt reduction of core body temperature. Secondary goals include repletion of fluids and electrolytes and management of resulting organ system dysfunction.
Cooling methods include:
Removal of occlusive/ wet clothing
Immersion in an ice bath
Application of ice packs to areas of major blood vessels (groin, armpits, neck)
Move to shaded area with application of fan and spraying cool water (evaporative cooling)
Oral intake of cool fluids (if mental status is appropriate)
How is heat stroke prevented?
Optimization of your hydration status prior to, during and after exposure to extreme temperatures and activity. Consumption of electrolyte containing beverages during activity that last more than 45 mins is recommended by the AAP.
Gradual increase of activity in hot and humid temperatures to get your body use to performing in those conditions.
Wearing clothes that are breathable and allows for evaporation of sweat (cotton versus synthetic fibers) balancing sun protection with the body’s ability to sweat.
Taking precaution in response to early signs of heat illness by hydrating and removing yourself from heat and decreasing/discontinuing activity.
Source: AAP, Up to Date