[NightCal]

I'm still trying to learn the techniques involved in capturing DSLR astro images. I known that I need dark frames to calibrate my image by taking out the thermal signal created by the camera. I also know that I need to have a set of darks of the same exposure length, ISO setting and temperature as the light frames. I'm planning to build up a 'bank' of dark frames of different ISO settings,temperatures and exposures. Now here is my question - the temperature of what? Should it be the outside temperature, the camera body temperature or the camera sensor temperature? I can get the outisde temp from a sensor/thermometer and the sensor temperature from the image EXIF file. For the camera body temperature I guess I would have to get a temperature sensor and tape it to the camera body.