The ability of the body to produce and eliminate heat is measured in terms of body temperature. The body is naturally able to maintain a safe temperature at all times, irrespective of changes in environmental temperatures. When the body is exposed to excess heat, there is an expansion of the blood vessels so that more heat can be transferred to the surface of the skin. Sweating takes place and when evaporation of the sweat occurs, the body is cooled. When the body is exposed to excess cold, there is a contraction of the blood vessels so that there is a reduction in the flow of blood to the skin. This allows for conservation of bodily heat. Shivering may also occur which is actually quick contractions of the muscles. This type of activity allows for further generation of heat.
Body temperature is measured in order to detect fever. It may also be used to detect hypothermia in individuals that have suffered exposure to excess cold, and in detecting hyperthermia in individuals that have suffered exposure to excess heat. Measuring the body temperature also helps to evaluate the progress of medications aimed to reduce fever. Body temperature is also a good way to detect ovulation in a woman, and hence can be used to plan a pregnancy.
The body temperature must be taken frequently when the individual is well so that the normal body temperature may be recorded. Body temperature varies during the day and hence must be measured in the morning and evening. The temperature must be taken about thirty minutes after drinking cold or hot beverages, smoking or waiting. Also, after exercise or a hot bath, one must wait at least for an hour before taking body temperature.
There are many methods for measuring body temperature. The most common method is oral temperature. The thermometer must be placed beneath the tongue to one side and the lips must be closed around it tightly. Allow it to remain inside for the necessary period of time. Remove and then read the measurement. Rinse the thermometer with soap and water before keeping it away. Other methods of measuring body temperature include taking rectal temperature, armpit temperature, ear temperature, forehead temperature and pacifier temperature.
Normal body temperature is taken to be 98.6 degrees F. There may be a slight increase or decrease of 1 degree F. Rectal and ear temperatures may be 1 degree F higher than oral temperature. Forehead temperature may be lower that oral and rectal temperatures.