Methods for core temperature measurements

The measurement of core temperature is important for many clinical situations including heat illnesses, hypothermia, infections, sepsis, shock, hemorrhage, and exposure to chemical and biological agents. Currently, oral and rectal temperatures are clinically utilized for such measurements. However, oral measurements are not always possible and accurate whereas rectal measurements are not convenient in the field, are labor intensive, use fragile glassware containing mercury--an environmental contaminant, require sterilization and are not suited for mass casualties. A simple, non-invasive, non-breakable, inexpensive device to measure core temperature, which is not labor intensive, would have great use in the field and in hospitals, as well as provide an important advance in instrumentation for experimental physiology. The purpose of this work is to evaluate the different methods for core temperature measurement. Since the middle of the 18th century, the mercury thermometer has been almost the only instrument for measuring core temperature. Today, more sophisticated methods and instruments are gaining popularity. In addition, new promising converted techniques, which are about to enter the market and increase the available variety of instruments, might improve the situation as far as reliability and convenience of use are concerned. Despite the importance and usage of this variable, the progress in this field has been slower than would have been expected.