Blizzards, floods, earthquakes, hurricanes, and tornadoes make headlines. They result in many tragic deaths each year. However, all of these natural disasters together do not kill as many people as heat stroke.
Heat-related illness often progresses from heat cramps, to heat exhaustion to fulminant heat stroke. Heat cramps are exertion-induced muscle contractions that develop during or after exercise in high temperatures.
Heat exhaustion is a clinical syndrome of fatigue, weakness, nausea, dizziness and malaise. Syncope or fainting may occur, but mental status usually remains normal. Heat Stroke is life-threatening hyperthermia which provokes a severe systemic inflammatory response with multiple organ dysfunction or failure. Simply put, heat stroke is deadly.
The clinical presentation of heat stroke typically falls into two categories: (1) classic and (2) exertional.
- Classic heat stroke often evolves over 2 to 3 days of exposure to extreme temperatures during a heat wave. Infants and older, sedentary, frail people without access to air- conditioning and adequate fluids are at greatest risk. Classic heat stroke was responsible for hundreds of deaths in Europe during the severe heat waves in 2003. A similar situation has recently occurred in India.
- Exertional, heat stroke develops more abruptly in healthy, active people like athletes, people working outdoors or military recruits. High level exertion in extreme heat overwhelms the ability of the body to regulate internal temperature. Muscle tissue breaks down, renal failure develops, brain functions are severely compromised, and clotting disorders develop.
People with heat stroke are often confused and agitated. They can injure themselves & others before they collapse into seizures and comma.
One of the most important early clues to the recognition of heat stroke is the cessation of sweating despite exertion in extreme heat and humidity. The skin becomes hot & flushed but dry.
This is a very worrisome sign since perspiring is a crucial part of regulating internal body temperature. At this point, the pulse and respiratory rate are usually elevated.
Initial treatment of heat stroke in the field involves evaporative cooling by constantly wetting the skin with water (ice water is not necessary). Cold packs can be applied to the groin and axillary area.
Seizures, vomiting, and aspiration can develop during cooling, so the airway must be protected. Curiously, typical fever-reducing medications such as aspirin, acetaminophen, or ibuprofen are ineffective in lowering body temperature in heat stroke. Transport to the nearest hospital and ICU (Intensive Care Unit) are essential.
Preventing heat stroke is obviously much easier than treating it. Common sense measures such as avoiding exertion in high heat and humidity, staying well- hydrated and remaining in an air- conditioned environment are key. Special attention should always be paid to infants, children, the elderly and chronically ill. If ever there were a condition where an ounce of prevention was worth a pound of cure, it would surely be heat stroke.
Learn more about heat stroke and other heat related illnesses in our homestudy courses.