'n Eksperimentele ondersoek van oorkanaaltemperatuur as meting van kerntemperatuur by die mens

Abstract

The human body is frequently exposed to extreme heat in performing one's daily task. Overexposure to these conditions may lead to deviations and hyperthermia. Such abnormalities may have fatal consequences if no steps are taken to rectify the condition. Various methods and localities are used to measure core temperature. The most common method of determining core temperature is by measuring an individual's rectal temperature. However, this causes discomfort and sometimes pain and is also considered unethical. It was therefore decided to examine the possibility of ear canal temperature as a measure of core temperature. Ear canal temperature was compared with rectal temperature. Thirty male subjects between the ages of 18 and 23 took part in the experiment. Twenty subjects performed a workload of 75 watts per minute during which the ambient temperature was kept constant at 26 °C. Rectal and ear canal temperatures stabilised after approximately 30 minutes, resulting in a very stable T /To ratio. During another phase of the experiment, ten subjects were exposed to an ambient temperature of 40 °C at rest. Rectal temperature stabilised after a certain time but ear canal temperature showed a steady increase towards the end of the experiment. This constant increase was most probably caused by the higher ambient temperature, which resulted in an elevated skin temperature. Because the cavity in the auditory canal is lined with skin, a higher ambient temperature would result in an increased auditory canal temperature. Skin temperature could never exceed core temperature, however, and ear canal temperature would therefore be a very accurate measure of core temperature. According to the results of this study it is possible to make a successful prediction of core temperature by ear canal temperature measuring.