As summer approaches, athletes, coaches and other individuals will need to be aware of heat-related illnesses. Heat illnesses include a spectrum of conditions ranging from heat syncope, heat cramps and heat exhaustion to the more severe heat stroke.
Heat Syncope (fainting) is a form of orthostatic hypotension that is related to dehydration. It occurs due to inadequate cardiac output and hypotension. It also occurs with standing quickly after sitting or lying down for prolonged durations in the heat. Symptoms include fainting, dizziness and light-headedness. Treatment includes oral rehydration (water, juice or sports drinks) and placing the patient flat on the ground in a cool area with slight elevation of the legs to push the blood back to the vital organs such as the brain.
Heat Cramps are painful muscle cramps that occur due to decreased sodium 
concentration in the blood. The patient’s core temperature is usually not elevated. Sodium may decrease when salts are lost in sweat or with excessive water intake that does not include electrolytes leading to a situation called dilutional hyponatremia. Symptoms include painful muscle cramps occurring commonly in the abdominal muscles, arms, legs and thighs. Treatment includes rest, cooling and IV fluids or oral rehydration with fluids rich in electrolytes (sports drinks and juices) to replenish the sodium stores. Prevention could be achieved by consumption of fluids high in electrolytes before strenuous activities.
Heat Exhaustion is the most common heat illness. The body temperature becomes elevated but is less than 40°C. The core body temperature is best measured rectally. The signs and symptoms of heat exhaustion include profuse sweating, core body temperature lower than 40°C, weakness and fatigue, cramping, headaches, nausea and vomiting, fainting, hypotension, increased heart rate, and fast shallow breathing. Treatment includes rest, IV fluids or oral rehydration and rapid cooling by whole-body immersion in an ice bath.
Heat Stroke is the most severe form of heat illness. It is a medical emergency that needs immediate attention. The patient should be transported to the hospital as soon as possible. Heat strokes occur due to failure of the body’s normal thermoregulatory mechanism. If treatment is not started promptly, end-organ failure and ultimately death may occur. Heat strokes have a high mortality rate and require quick reduction of the patient’s temperature. The three characteristic features of this condition are a lack of sweating, core body temperature above 40°C (best measured rectally) and an altered mental status. Additional signs and symptoms include hot, dry skin, disorientation, confusion and hallucinations, headache and slurred speech. This is a serious medical emergency that requires rapid core body temperature reduction. The patient should have close monitoring of airway, breathing and circulation. The physician should implement basic life support and ACLS protocols. Rapid cooling by whole-body immersion in an ice bath will be utilized as well as IV fluids.
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