The body temperature of a human being is an indication of his physical condition, so that an abnormally high or low temperature is generally a sign that something is wrong.
The normal temperature is usually given as 36.90 C. (98.40 F.), but as the body temperature varies throughout the day, anything between approximately 36.70 C. (OR 98.10 f.) and 37.20 C. (or 99.00 F.) may be taken as normal.
For instance, the temperature rises after a large meal, during hot weather and after violent exercise. Your temperature is at its lowest at night when you are asleep.
Control of body temperature is exercised by a centre in the brain which ensures that a balance exists between heat production and heat loss. A raised temperature is often the sign of bacterial or virus infection. It may be due to heatstroke, to certain types of brain injury or disease or to shock.
A very high temperature, or fever, may begin with a “rigor” (an attack of shivering and cold), in which the whole body may tremble uncontrollably and the teeth chatter. Although at this stage the skin feels cold and clammy, the temperature within the body is raised. Soon the skin becomes hot and dry, pulse and breathing rate are speeded up and there is a feeling of exhaustion, aching muscles. Headache, thirst and perhaps delirium and loss of the sense of time.
Finally this stage is succeeded by profuse sweating and a gradual relief of the symptoms.
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