Heat Stroke: Deadly but Preventable

Abstract

A severe wave with temperature as high as 49 oC(120oF) struck southern Pakistan in June 2015. It caused deaths of approximately 2000 people from dehydration and heat stroke mostly in Sindh province and its capital city Karachi.Mr.AsifShuja former DG of Pakistan Environmental Protection Agency claimed that heat wave was a symptom of global climate change, aggravated by de-forestations, expansion asphalt highways and rapid urbanisation1.Dunya News reported at least 1360 patients died due to heat stroke in different hospitals of Karachi2. HEAT EXPOSURE SYNDROME: Four medical disorders comprise a spectrum of illness that can result from exposure to hot environments (1)Heat Cramps(2)Heat Syncope(3)Heat Exhaustion And (4)Heat Stroke.Health conditions that inhibit sweat production or evaporation and increase susceptibility to heat disorders include Obesity, Skin disorders (Miliaria),Reduced cutaneous blood flow(by use of vasoconstrictors and beta adrenergic blocking agents) ,Dehydration ( by use of alcohol and illicit drugs e.g. phencyclidine, LSD, amphetamines and cocaine),Malnutrition,Hypotension and reduced cardiac output,Medications such as anticholinergics, antihistamines, phenothiazines, tricyclic antidepressants, monoamine oxidase inhibitors, diuretics etc.Risk of heat disorder increases with (1) Age (2)Impaired cognition (3) Concurrent illness(4) Reduced physical fitness (5)Insufficient acclimatization etc3. HEAT STROKE: Heat Stroke is a life threatening medical emergency that results from failure of thermo-regulatory mechanism. It is imminent when the core (rectal) temperature approaches 41oC or 105oF and presents in one of two forms: (a) Classic heat stroke that occurs in patients with compromised homeostatic mechanisms. (b) Exertional heat stroke that occurs in healthy persons undergoing strenuous exertion in a thermally stressful environment4