Core temperature measurement - Methods and current insights

Climatic injuries, including hypothermia, hyperthermia and heat stroke, are common in many sports activities. Body core temperature (T-c) measurement for the sportsperson can influence individual performance and may help to prevent injuries. Monitoring internal body T-c accurately requires invasive methods of measurement. The mercury thermometer, most commonly used to measure oral temperature (T-oral), has been almost exclusively the only instrument for measuring T-c since the 18th century. Rectal (T-re) and oesophageal temperatures (T-oes) have been the most preferred measurement sites employed in thermoregulatory investigations. However, these measurement sites (T-re, T-oes, T-oral), and the methods used to measure T-c at these sites, are not convenient. T-oral measurements are not always possible or accurate. T-oes is undesirable because of the difficulty of inserting the thermistor, irritation to nasal passages and general subject discomfort. T-re is not suitable under many circumstances as it is labour intensive and has a prolonged response time. However, T-re remains the most accurately available method for monitoring T-c in thermal illness that occurs during sports activities. In addition, T-re and T-oes require wire connections between the thermistor and the monitoring device. The purpose of. this paper is to review the various existing methods of T-c measurements in order to focus on the breakthrough needed for a simple, noninvasive, universally used device for T-c measurement which is essential for preventing climatic injuries during sports events.