Beware of heat stroke

MOTUNRAYO JOEL writes about the symptoms, causes of heat stroke and how it can be treated

Heat stroke is a medical condition. This happens when the human body’s cooling mechanisms are overcome by heat, resulting in a high score heat usually about 104 F or 40 C in adults and 105 F or 40.5 C in children. It is often characterised by fever and then, unconsciousness.

Otherwise referred to as sun stroke, this condition is considered a medical emergency.

But this condition is different from a fever, where there is a physiological increase in the temperature set point of the body. The term ‘stroke’ in the word heat stroke, is a misnomer in that it does not involve a blockage or hemorrhage of blood flow to the brain.

Heat stroke generally presents with a hyperthermia of greater than 40.6 °C (105.1 °F) in combination with disorientation and a lack of sweating.

Before heat stroke occurs, sufferers show signs of heat exhaustion such as dizziness, mental confusion, headaches, and weakness. However, if it occurs when the person is asleep symptoms may be harder to notice.

A symptom of this condition in young children is seizures, unconsciousness, organ failure, and then death.

With the heat experienced lately, there is the need for caution. According to studies, heat stroke occurs when thermoregulation is overwhelmed by a combination of excessive metabolic production of heat (exertion), excessive environmental heat, and insufficient or impaired heat loss, resulting in an abnormally high body temperature.

On the common causes of heat stroke, many medical experts listed exposure to hot environment as a factor.

A respiratory physician, Dr. Cajetan Onyedum, explains that,  “In a type of heatstroke, called non exertional or classic heatstroke, being in a hot environment leads to a rise in body temperature; and this type of heatstroke typically occurs after exposure to hot, humid weather, especially for prolonged periods, such as two or three days. It occurs most often in older adults and in people with chronic illness.”

Onyedum added that engaging in strenuous activities could also lead to heat stroke, if not properly maintained.

“Exertional heat stroke is caused by an increase in body temperature brought on by intense physical activity in hot weather. Anyone exercising or working in hot weather can get exertional heatstroke, but it’s most likely to occur if you are not used to high temperatures,” he said.

In either type of heatstroke, one’s condition can be brought on by the following: wearing excess clothing that prevents sweat from evaporating easily and cooling your body; drinking alcohol, which can affect your body’s ability to regulate your temperature; and becoming dehydrated by not drinking enough water to replenish fluids lost through sweating.

Young people – athletes, outdoor labourers, and personnel engaged in hot-weather activity or wearing heavy personal protective equipment, can experience exertional heat stroke. In environments that are not only hot but also humid, it is important to recognise that humidity reduces the degree to which the body can cool itself by perspiration and evaporation

Onyedum opined that anyone can develop heatstroke, but several factors increase one’s risk, one of which is age.

He said, “Your ability to cope with extreme heat depends of the strength of your central nervous system. In the very young, the central nervous system is not fully developed. For adults over 65, the central nervous system begins to deteriorate, which makes their bodies less able to cope with changes in their body temperature. However, both age groups usually have difficulty remaining hydrated, which also increases risk.

“Sudden exposure to hot weather is another factor. You may be more susceptible to heat-related illness if you are exposed to a sudden increase in temperature, such as a trip to a hotter climate. Limit activity for at least several days to allow your body acclimatises to the change. Another factor is lack of good air conditioning devices. Fans may make you feel better, but during sustained hot weather, air conditioners are the most effective way to cool down and lower humidity.”

Onyedum advised against medications that affect’s one’s body ability to stay hydrated and respond to heat.

“Be especially careful in hot weather if you take medications that narrow your blood vessels (vasoconstrictors), regulate your blood pressure by blocking adrenaline (beta blockers), rid your body of sodium and water (diuretics), or reduce psychiatric symptoms (antidepressants or antipsychotics),” he said.

Citing more symptoms of the condition, a general practitioner, Dr. Omoyili Cynthia said apart from high body temperature, nausea and vomiting could be another symptom.

She said, “Altered mental state or behaviour – confusion, agitation, slurred speech, irritability, delirium, seizures and coma can all result from heat stroke. Alteration in sweating is another symptom. In heat stroke brought on by hot weather, your skin will feel hot and dry to the touch. However, in heat stroke brought on by strenuous exercise, your skin may feel moist. Nausea and vomiting are also symptoms. You may feel sick to your stomach or vomit. Other symptoms include flushed skin whereby your skin may turn red as your body temperature increases.

“Other symptoms include rapid breathing, when your breathing may become rapid and shallow, racing heart rate and heart ache. The risk of heat stroke can be reduced by observing precautions to avoid overheating and dehydration.”

A general practitioner, Dr. Rotimi Lawal, speaking on the preventive measures, explained that light, loose-fitting clothes are suitable for hot weather.

“This type of outfit allows perspiration to evaporate and cool the body. Wide-brimmed hats in light colours help prevent the sun from warming the head and neck. Vents on a hat will help cool the head, as well sweatbands wetted with cool water, especially for athletes. Strenuous exercise should be avoided during daylight hours in hot weather; so should remaining in confined spaces without air-conditioning or adequate ventilation.

“In hot weather, people need to drink plenty of cool liquids to replace fluids lost from sweating. Thirst is definitely not a reliable sign that a person needs fluids. A better indicator is the colour of urine. A dark yellow colour may indicate dehydration. The same cholesterol plaques that can build up in the arteries surrounding the heart can also affect arteries that go through penile tissue.”

However, Lawal said that heat stroke can result in a number of complications, depending on how long the body temperature is high.

“Complications include vital organ damage. Without a quick response to lower body temperature, heat stroke can cause your brain or other vital organs to swell, possibly resulting in permanent damage. Without prompt and adequate treatment, heat stroke can be fatal leading to death,” he said.

Heat stroke treatment centers on cooling your body to a normal temperature to prevent or reduce damage to your brain and vital organs. To do this, your doctor may take these steps:

Other measures, according to Lawal include immersing the patient in cold water.

“A bath of cold or ice water can quickly lower your temperature. Evaporation cooling techniques are very helpful. Some doctors prefer to use evaporation instead of immersion to lower the patient’s body temperature. In this technique, cool water is misted on their skin while warm air fanned over the patient’s body; this causes the water to evaporate, cooling the skin. Another procedure is to pack the victim with ice and cooling blankets or to wrap the person in a special cooling blanket and apply ice packs to their groin, neck, back and armpits to lower their temperature.

Lawal said the patient could also be given medications to stop shivers.

“If treatments to lower your body temperature make you shiver, your doctor may give you a muscle relaxant. Shivering increases your body temperature, making treatment less effective. The person’s condition should be reassessed and stabilised by trained medical personnel. The person’s heart rate and breathing should be monitored properly,” he said.

Coming in to summer we want you to be aware of the risks involved with heatstroke. Canberra is looking at having another hot summer and we want you to be prepared by making sure you follow some of the above listed advice to stay cool. Also you could attend a Canberra first aid course and learn more about the signs and symptoms and treatments of hyperthermia and heat stroke. We run first aid courses in Canberra every week however our training is booking up for the rest of the year. Book in now to one of our first aid courses.

We would also like to thank for the use of this excellent article.

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