The aim of this study is to assess the impact of different environmental factors on the ability for a thermistor-based epitympanic thermometer to accurately read the temperature of a normothermic individual and thereby estimate their feasibility and reliability in the austere pre-hospital setting.~Healthy volunteers will be recruited. As reference value for core temperature we will use a standard rectal probe (Mon-a-Therm, General purpose Temperature Probe 12Fr/Ch, Covidien) attached to an external monitor. The study will be in a field setting in the mountains of Hemsedal, Norway.~For measuring the epitympanic temperature we will use the Metraux Thermometer (Walpoth, Galdikas et al. 1994). The Metraux Thermometer is widely used in pre-hospital care in Norway and internationally. The ear-sensor will after induction of anaesthesia be inserted according to the manufacturers specifications in the auditory canal and activated. The sensor is two tiny and soft metal wires covered in a plastic wrapping integrated in a soft rubber earplug. The depth of the measuring point is pre-set from the manufacture to be approximately 10 mm from the tympanic membrane. The display will then show the epitympanic temperature in real-time.~The volunteers will be exposed to four different scenarios. 1. Ambient air with no protection of head/measuring site. 2. Ambient air with local protection of measuring site. 3. Snow in the ear-canal before placing the thermometer (to resemble avalanche conditions). 4 Cold water in the ear canal (to resemble water immersion/submersion).~The temperature will be measured in degrees Celsius. A baseline will be established before exposing the volunteers to the different environmental factors. After exposure the temperature will be recorded every 15 seconds for a total of 10minutes.
The aim of this study is to assess the impact of different environmental factors on the ability for a thermistor-based epitympanic thermometer to accurately read the temperature of a normothermic individual and thereby estimate their feasibility and reliability in the austere pre-hospital setting.