A methodology for the real-time measurement of distal extremity temperature.

The real-time measurement of distal extremity temperature may have a wide variety of uses, from assessing occupational cold exposure to determining the impact of autonomic dysfunction on normal thermoregulation. In this study, we describe a novel approach to the measurement of this physiologic parameter by the use of datalogger iButtons affixed to the foot and outer clothing, the latter serving as an approximate measure of ambient temperature, in conjunction with the measurement of foot movement via actigraphy. This approach was piloted in 20 individuals, all of whom were also requested to maintain a diary of activities during the measurement period. The technique was found to be reliable and well tolerated amongst the group of subjects, with no individual suffering an adverse reaction (e.g. skin breakdown) while wearing the device. However, periods of ambient temperature data were suspect in at least 25% of the recordings, presumably due to misplacement of the sensor. Several approaches to data analysis suggested themselves, including separate analysis of the nocturnal/sleep and awake data sets. The use of datalogger iButtons in conjunction with actigraphy appears to be a potential useful approach for the acquisition of real-time distal extremity temperature and movement data and has the potential of serving a variety of clinical and research purposes.