The human body usually regulates its body temperature well. Problems arise when the body ceases to cope with thermoregulation when exposed to very high temperatures.
It can be very hot both indoors and outdoors, but urgent conditions can occur even when the temperature is not very high. A person's tolerance to heat depends on air humidity, wind, clothing, living and working conditions, physical activity, age and health.
Heat cramps, heat exhaustion and heat stroke are caused by high temperatures. Muscle cramps are the least serious problem, but can lead to heat exhaustion or heat stroke. Heatstroke is a medical emergency and can cause coma and death if necessary measures are not taken to cool the body.
Anatomy and physiology of hyperthermia emergencies
For normal functioning of the body, body temperature must remain unchanged. A body temperature of 36.6°C is considered normal. When food is converted into energy and muscle contractions, the body produces heat.
Heat always spreads from warm areas of the body to colder ones. Since the human body is usually warmer than the surrounding air, it tends to radiate heat outward. The body regulates body temperature through a constant balance between heat loss and heat production (Figure 11-3). The heat produced by daily activities is usually sufficient to compensate for average heat losses. When the amount of heat in the body increases, its excess is released through the skin. The blood vessels in the skin dilate to give off more heat. Heat is removed from the body and the body cools down
When the ambient temperature is high, the main means of cooling is the evaporation of sweat. Sweating increases as body temperature rises. But when the ambient air humidity is high, sweat evaporates slowly, which does not lead to a cooling effect.
Causes of hyperthermia emergencies
Hyperthermia is caused by excess heat in the body. This depends on factors such as ambient temperature, humidity, and wind strength. Physical activity or sports in hot conditions increases the risk of medical emergencies. Certain individual factors may contribute to the occurrence of such conditions in some individuals, including:
•physical work or outdoor sports; • old age;
•infancy;
• health problems;
• diseases associated with overheating in
past;
• heart disease or other conditions that you
called circulatory disorders;
• taking medications that contribute to
remove fluid from the body (diuretics
facilities).