The internal body temperature should stay within the normal range around 98.6 Fahrenheit or 37 Celsius at all times. The temperature on the surface of the body (skin) varies to some degree depending on the climate but the body has various mechanisms to ensure that the internal temperature stays constant. If the internal temperature drops dangerously low level then it is as hypothermia. When it rises significantly usually a above 104 Fahrenheit or 40 Celsius then it is known as hyperthermia. This high body temperature can occur due to very hot weather or physical activity in a hot environment and is referred to as a heat-related illness.
There are three forms of heat related illnesses – heat cramps, heat exhaustion and heat stroke. Of these three forms, a heat stroke is a medical emergency that is potentially fatal. A heat stroke is preceded by heat cramps and then heat exhaustion.
Heat cramps is the first and mildest form of a heat-related illness. The loss of fluid and electrolytes, commonly referred to as water and salt, disrupts the normal body processes. This is evident as periods of rapid contracting and relaxing of the muscles, also known as spasms or sometimes even twitching.
Heat exhaustion in the second form of a heat-related illness. The muscle spasms seen in heat cramps is present along with other symptoms like nausea, vomiting and weakness. Heat exhaustion precedes a heat stroke, however, the differentiation between heat cramps, heat exhaustion and heat stroke is often difficult to make.
Heat stroke in the final and most severe form of a heat-related illness. At this point of the body’s temperature has usually exceeded 104 Fahrenheit or 40 Celsius and without medical intervention, death may occur. A heat stroke is preceded by heat cramps and then heat exhaustion. It is marked by the presence of the symptoms of both heat cramps and heat exhaustion along with more serious features such as :
Heat-related illnesses occurs when the body is no longer able to maintain a normal internal temperature within a hot environment. As the internal body temperature rises, and there is excess of loss of fluid and electrolytes and sweating, the bodily processes are disrupted. This often occurs in summer months, especially if there is a heatwave, but can occur even in moderately high temperatures when a person undertakes strenuous physical activity in a hot environments.
The elderly are considered to be a high risk group four developing heat related illnesses because the normal mechanism that controls the internal body temperature becomes impaired with age. This thermoregulatory mechanism may also be affected with certain types of diseases and the use of some chronic medication which is more common in the elderly.